City of Heroes Coldfront (CoH, CoV)

Temporary Invulnerability
TI provides a base 30% RES to S/L when active. It is a toggle power, which means it costs endurance to keep running. Plus, it can be turned off by things that de-toggle, like status effects, PvP Brawl, or endurance drain.
TI is enhancable with damage resistance, endurance reduction, and rechage enhancements. TI really recharges too quickly for recharge to be useful. However, it has a moderate endurance cost, so endurance reduction may be worth considering, especially with the reduced effectiveness of Stamina post-ED.
Three-slotted with even-level damage resist enhancements, TI will provide: 34.5 S/L RES (TO’s), 39% S/L RES (DO’s), or 47% S/L RES (SO’s). Note that six-slotted with SO’s, TI does reach almost 50% S/L RES.

Recommendation: 3-slotted TI is likely to be considered a necessity for an Inv tanker in I5. As mentioned earlier, S/L is the most common damage type in Paragon City, and without TI, you won’t get beyond 21% S/L RES. In my builds, this is the first power I take and I usually target having it 3-slotted by lvl 10. Since it has such a high base, even TO’s and DO’s actually provide some benefit for this power. For example, at lv 12, if you can afford three DO's, this power will get you to 39% S/L RES.
Some folk will likely slot one endurance reduction in TI. I have even seen builds with two. At the moment, folk don’t really have a good feel for endurance costs in an ED world. For now, plan to slot endurance reduction as needed. It is certainly more effective to slot EndRdx in attacks first. However, if you still find you need to reduce your endurance use, the next target should be your toggles. The currently published endurance costs for the toggles are 0.38/s for TI, 0.4 for UY, 0.28 for Invinc, and 0.5 for Tough, so the order for slotting EndRdx in toggles is Tough, UY, TI, and Invinc.

Dull Pain
When activated, DP increases your health by 40% and provides some healing. Its worth reading Stupid_Fanboy’s Dull Pain: How it works, How to use it guide.

Recommendation: Most tanks will recommend taking DP in I5. There are three major considerations that lead to this. First, in the early levels, when your defenses are fairly undeveloped, 40% more hit points goes a long way towards improving your survivability.
Second, post-I4, an Inv tank simply cannot develop strong non-S/L RES. At the later levels, when non-S/L damage becomes more prevelant, DP provides an extra buffer of damage you can take and still survive.
Finally, perhaps the most compelling reason is DP affects your regeneration rate. The amount of health you regenerate is actually a percentage of your overall health. So, the greater your total health, the more health you recover per second. If you combine DP with 3-slotted Health, you can significantly boost your regen rate when DP is active. If you're taking a build approach that does not cap S/L RES or only includes very minimal non-S/L RES, you should consider the DP and Health combination.

Resist Elements
REl provides a base 7.5% RES to Fire/Cold/Toxic damage. Like RPD, REl is a passive power, so it is always active.
REl is only enhancable with DamRes enhancements. As a result, it is not recommended you devote more than three slots to this power.
Three-slotted with even-level enhancements, REl will offer 8.625% F/C/T RES (TO’s), 9.75% F/C/T RES (DO’s), or 11.7% F/C/T RES (SO’s).

Recommendation: REl got hit pretty hard in I5 and then got hit a bit more with ED. With the drop in REl and UY, 3-slotted UY and REl will only get you 27.57% F/C/T RES. In I4, the same combination used to reach 88%. You will notice this difference.
This change has resulted in three main strategies for approaching REl. A lot of folk feel the drop is significant enough to warrant leaving REl out of their builds entirely. If you do take REl, many tanks are finding ED leaves them with so many unused slots, they may as well 3-slot it, even though the relative benefit is fairly small. A third strategy might be to take it and leave it with the base slot. The path you take is purely personal preference.
It should be noted that most of the significant non-S/L damage-dealing foes don’t pop up until later in the game, so many folk put off getting REl until the mid-to-late 20’s. The prevalence of Vahzilok missions in the early game may change this, now that REL and UY have Toxic RES. However, you can certainly survive without REl through the early levels.

Unyielding
UY provides status protection, RES to S/L (5% base) and Fire/Cold/Energy/Negative/Toxic (10%), and a 5% DEF debuff – yes, you will be hit 5% MORE with UY active.
UY is enhancable with damage resistance, endurance reduction, and rechage enhancements. UY really recharges too quickly for recharge to be useful. However, it has the highest endurance cost of all the Inv primary powers, so endurance reduction may be worth considering, especially with the reduced effectiveness of Stamina post-ED.
Three-slotted with even-level enhancements, UY provides: 5.75% S/L and 11.5% non-S/L RES (TO’s), 6.5% S/L and 13% non-SL RES (DO’s), or 7.8% S/L and 15.6% non-S/L RES (SO’s).

Recommendation: For the status protection alone, this power is worth taking. There are a broader collection of opinions on whether or not its worth slotting. On the plus side, slotting this power provides additional RES for seven different damage types, even though its not a lot of additional RES per slot. You can certainly survive with this power single-slotted.
In my builds, I take UY as soon as its available and 3-slot it eventually. I tend to keep UY on all the time, so my philosphy is why not get the most out of it. Furthermore, my builds tend to slot defensive powers before offensive powers.
UY also takes EndRdx enhancements. As mentioned in the section on TI, you should slot these as needed. Certainly, since UY has the largest cost of all toggles in the Inv Primary, it will be one of your first candidates.

Resist Energies
REn provides a base 7.5% RES to Energy/Negative Energy damage. Like RPD and REl, REn is a passive power, so it is always active.
REn is only enhancable with DamRes enhancements. As a result, it is not recommended you devote more than three slots to this power.
Three-slotted with even-level enhancements, REn will offer 8.625% En/Neg RES (TO’s), 9.75% En/Neg RES (DO’s), or 11.7% En/Neg RES (SO’s).

Recommendation: Go back to the recommendation section for Resist Elements and substitute F/C/T for En/Ng as appropriate.

Invincibility
Invinc provides a DEF and ACC bonus for every foe, up to 14, in melee range. According to the Devs, it provides 1.5% S/L/F/C/En/Eg/T typed DEF for each foe. Testing seems to indicate if provides 3.5% melee DEF. I’m going to stick with the Tested numbers in this guide, but I’m a bit biased. Testing also indicates it provides around 3% ACC per foe in melee range.
In addition to its buffing effects, Invinc is also a Taunt aura, i.e. it Taunts foes within melee range.
Three-slotted with even-lvl DefBuf enhancements, Invinc provides: 4% DEF per foe (TO’s), 4.55% DEF per foe (DO’s), or 5.5% DEF per foe (SO’s).
Invincibility is slottable with defence buff, accuracy buff, endurance reduction, recharge, and taunt duration enhancements. Invincibility’s recharge is short enough to make recharge enhancements effectively useless. However, all other enhancements are viable.
Three-slotted with even-lvl AccBuff enhancements, Invinc provides: 3.45% ACC per foe (TO’s), 3.9% ACC per foe (DO’s), or 4.7% ACC per foe (SO’s).

Recommendation: In I5, Invinc arguably becomes the most important power in the Inv Primary. Think about it this way … if you three-slot Invinc with DefBuf SO’s, each foe in melee range will give you 5.5% DEF. In order to floor a minion’s to-hit, you will need to get eight foes in melee range. That’s pretty amazing … just eight foes in melee range and suddenly every minion pounding on you has no better than a 5% chance to hit.
My recommendation is to take this power and three-slot it with DefBuf’s as quickly as possible. Three-slotted with SO’s, you’ll need just 8 foes in melee range to floor even-con minions. Unslotted, it will take nearly 13. I wouldn’t get fanatical about it, tho. Many folk do perfectly well without slotting Invinc for DefBuf at all. I just personally think is a small investment for a pretty big gain if you plan to be on teams amidst large numbers of foes fairly often.
Invincibility is fourth on the list of toggles to slot for endurance reduction. Slot Tough, UY, and TI first before putting one here.
Accuracy buff and taunt duration are worth considering for slots beyond the first three. Accuracy has the same advantage as DefBuf. If you plan to be teaming a lot and expect to be surrounded by many foes, you’ll get an even bigger boost from these slots. Don’t forget about TntDur.

Tough Hide
Tough Hide is a passive power that provides base 5% S/L/F/C/En/Neg typed DEF. As a passive power, it takes no endurance and is always active.
Tough Hide only accepts Defense Buff enhancements, so it is recommended you stop at three slots.
Three-slotted with even-level DefBuf enhancements, TH provides 8% DEF (SO’s).

Recommendation: Taking TH and leaving it single-slotted is enough to counter the DEF debuff in UY. If you take it and 3-slot it, you’ll get an 8% DEF bonus. In combination with UY and Invinc, this means one fewer foe in melee range needed for Invinc to floor minion accuracy.
In my builds I typically take TH late and leave it single slotted. With ED, I think there will be enough slots in most builds to 3-slot it. If you consider the numbers, its certainly a better power to slot than UY. In fact, I would suggest if you decide to not slot UY or eliminate REl and REn from your build, you should consider three-slotting TH.

Unstoppable
Unstoppable is a click power that provides a base 70% RES to S/L/F/C/En/Ng/T. In addition, it provides status protection and improves your endurance recovery rate. It comes with a price … when it subsides, you are left with 10% health and no endurance.

Recommendation: I expect some debate about the importance of US in I5. It is certainly worth taking for emergency situations. Not only does it provide great RES, but it provides toggle-less RES … it is a click power. So, as long as it is active, its benefits cannot be de-toggled. This can be a great advantage by itself in PvP and against endurance draining foes, like Malta Sappers.
In I5, its also a power that temporarily time-warps your tank back to I4. For the three-minute duration of US, you will easily be able to cap RES in S/L/F/C/En/Ng/T. In fact, two DmgRes in US allow you to reach the cap for all seven of its damage types without any other powers. Of course, US's end boosting effect means most tanks won't bother to turn off their other powers when they click US, so this may be overkill. If you have single-slotted UY and one DmgRes in US, you'll still be over the cap for everything. In fact, six-slotted UY with and no DmgRes in US still gets you over in most damage types and close in S/L.
Because of its inherent high RES, US can be a great boon against non-S/L AV's, who appear in droves in the 40+ levels. These foes can do significant non-S/L damage, and since they're single foes, Invinc won't help much. US will let you tank them for three minutes. Just be warned, a lot of AV battles will last longer than three minutes, so be prepared to have enough fire-power along to keep the battle short, or have a plan that allows your teammates to pick up the slack when you disengage from battle just before US drops.
Another option is to slot US with Recharge enhancements. I have heard a number of tanks plan builds around keeping US active as much as possible – certainly a viable strategy; one which can free up a lot of slots and power choices! Note that, as of I5, US cannot be made permanent.

Fire Melee
==================================================
Fire melee has the advantage of being the secondary with the most area-of-effect (AoE) attacks. For this, its pays two noticeable prices. First, unlike most other Tanker secondaries, it doesn’t have any status effect attacks, i.e. you won’t get any attacks that disorient or knockdown foes. Second, in the later game, you find a reasonable number of foes with pretty good Fire resistance.

This might be a good time to talk about general offensive slotting strategy. ED has had a major effect on how tanks slot their offenses. Prior to ED, many tanks five or six-slotted their main attacks with Damage enhancements catering to the philosophy that a defeated foe is one you don't need to resist or defend against.
With ED, this is no longer a viable strategy. Instead, most folk will now have to decide what to slot their attacks with beyond the first three damage enhancement slots.
You will likely still want to six-slot your main attacks, but you may find some of those slots filled with ACC, TntDur, and EndRdx enhancements. For example, my personal approach is to slot most of my attacks with one EndRed, one Acc, one Recharge, and three Dmg. The EndRdx helps keep my endurance drain rate managable without needing Conserve Power. However, don't discount the possibility of TntDur in attacks. In I4 this wasn't terribly common practice because there wasn't a limit to the number of foes affected by Taunt. My current I5+ED build has TntDur in FSC and Combustion, to help with aggro management.

For some specifics, Cactus and Dracomicon posted a nice ED slotting guide for Fire Melee in the tanker forum in their Surviving ED - Slotting for Inv/Fire post.

Scorch
Scorch is a single target attack that does minor Fire damage with a chance of doing a small amount of follow-on Fire damage-over-time (DoT).

Recommendation: Well, you have to take it, so there’s really no point, right? I will say something about slotting, tho. A lot of folk recommend leaving this one unslotted. By level 40, there are typically enough other more powerful attacks available that this one comes out of your attack chain so, outside of a respec, some folk feel slots are just wasted in Scorch.
Still, this is an attack you're likely to use heavily in the first 20 - 30 levels, which is a pretty significant amount of time. Axterix pointed out to me that, if you plan on only six-slotting only one attack in the first 20 levels, Scorch really has a slight advantage over Fire Sword. You can use it a little more frequently, which gives it an advantage for Gauntlet (Punchvoke), it does a bit better DPS (damage-per-second), and it uses slightly less endurance. It is also true that, of all Tanker Secondaries, Scorch is probably one of the better mandatory attacks.

Fire Sword
Fire Sword is a single-target attack which does moderate Fire/Lethal damage and also does Fire damage over time.

Recommendation: Many Inv/Fire Tankers recommend skipping FS in favor of relying more heavily on the later AoE attacks. This is a perfectly viable strategy that frees up one power in the early levels.
If you find yourself to be the impatient type, like me, you may find relying on just Brawl and Scorch frustrating. So, in my builds i take FS to round out my early attack chain.

Taunt
Taunt is an auto-hit ranged power that allows you to take the aggro from the targeted foe and the next four closest foes (i.e. five total). Even with the new limited number of affected foes, Taunt is still a powerful tool for managing aggro.

Recommendation: A lot of controversy surrounded Taunt in I4, and its likely to just get worse in I5. Many folk feel the foe limit makes Taunt unnecessary in light of other aggro management tools like Punchvoke (Gauntlet) and Invincibility. Others feel with the reduced defensive stance in I5, they may not be able to survive the aggro, anyway. For those who still take it, there’s much debate over when to take it. Is it worth taking before you’ve built enough defense to survive its use or do you wait until you've built up reasonable defense? At what point do you cross that line?
Personally, I like to take Taunt when its available. In the early levels, your choices are limited, and I find level 4 to be a convenient time to grab it, even if I don’t use it right away. In I4, I had enough defense to use Taunt by around lvl 12-14. In I5, my early testing seems to indicate this hasn’t changed too much. Maybe 14-16 to be safe. However, taking Taunt early becomes a bit more problematic in I5 as there are actually some competing choices with RPD, DP, and FS.
If you decide not to take Taunt, learn to use your other aggro management skills effectively. Switch between foes to take advantage of Gauntlet (Punchvoke). Take advantage of Invincibility's taunt aura. Please try to be a good judge of how effective you are at doing this. If you find you simply can't manage aggro without Taunt, either take it or make sure to let your teammates know. Other AT's have always expected Tanks to manage team aggro, and some tanks even report being kicked from teams simply because they do not have Taunt. I’m not suggesting you let other players dictate your build and play style for you, but its something to be prepared for. And remember, you can avoid a lot of angst by simply telling your teammates what to expect.

On slotting, I would suggest slotting Taunt with recharges, especially if you aren't picking up Hasten. Taunt may only affect five foes, but each time you use it you can affect a different set of five. So having it available more often can help you manage a greater number of foes.

Combustion
Combustion is a moderate Fire damage DoT PBAoE (point-blank area of effect) attack, i.e. its an AoE attack with you at its center.

Recommendation: There are two things that surprised me about this power when I picked it up. First, at 15', Combustion has a great radius and can affect a large number of foes around you. Second, it starts out a bit slow for its endurance cost. Although Axterix has pointed out to me that its cost is only a little worse than FS and its more efficient if you can reliably hit three foes around you.
I will suggest Combustion should be part of your build at some point. Fire Melee is a strong AoE secondary, and Combustion is one of the two must-have AoE's in the set. If you have held off on single-target attacks in your early build, take Combustion when it becomes available and get it slotted.

Breath of Fire
BoF is a cone of fire you breathe from your mouth. It does Fire damage in a reasonably narrow cone, but has the benefit of increased base accuracy.

Recommendation: I’ve only had BoF in one of my builds and only for a short time before I respec-ed it out. Its not that horrible an attack, it just isn’t as good as the other AoE’s in the set. Plus, it comes at a very awkward time, when you’re busy trying to make sure to fit in a travel power and get set up to have Stamina. I still miss taking out Clockwork "Gears" with this power, tho.

Build Up
Build Up boosts your accuracy and damage for 10 seconds.

Recommendation: Not essential, but it is a good power. You should be aware it can’t be made perma. I had a long discussion with somebody about this once that I need to dig up and add here. The conclusion, however, was I don’t recommend adding more slots to it.

Fire Sword Circle
FSC is a moderate Fire/Lethal damage PBAoE attack. It has a shorter radius than Combustion, but it does more damage. When you use it, you will notice a strange pause between when the animation completes and when you can do something.

Recommendation: FSC in combination with Combustion makes for great Inv/Fire tanking. I would recommend both powers 6-slotted. You may seriously want to consider EndRed in these, even if you don’t use them in other attacks.

Incinerate
Incinerate is a single-target high Fire damage DoT attack.

Recommendation: When you get into the later game, you start to get opportunities to fight powerful single foes, like AV’s. In these battles, it helps a great deal to have the strong single-target Fire attacks. I definitely recommend taking Incinerate as part of your single-target attack chain.
Also, Axterix has pointed out to me that Incinerate is incredibly end efficient. It has the second-highest DPE of any Tanker Secondary attack, without the HP penalty.
Incinerate does take some getting used to, because the damage is spread out over a longer time frame than most other DoT’s. It takes some experience to get comfortable knowing Incinerate will do enough to take a particular foe out and you can switch to another foe. That’s probably the biggest downside to Incinerate – you’ll find you waste its DoT damage because you’ll swing again or a teammate will take out a foe that would otherwise be defeated by the follow-on DoT.

Greater Fire Sword
GFS is the strongest single-target attack in the set. Like FS it does a combination of Lethal and Fire damage and has a Fire DoT. Like FSC, it has a noticeable pause after the animation completes which can be unnerving.

Recommendation: I’d suggest taking GFS for the same reasons as Incinerate. In the late game, Incinerate and GFS will take a significant role in your battles with powerful single foes. Early on, I quickly make Scorch/FS/Incin my single-target attack chain. When GFS comes along, its easy to change to FS/Incin/GFS. Regardless of which single-targets you take, GFS and Incin are going to be the best damage-dealers.

Power Pools
==================================================
I’m not going to spend a lot of time on Power Pools. In my mind, they’re largely personal preference. I will comment on a couple specific powers.

Tough – As mentioned earlier, if you want to cap S/L RES, with ED you now need to include Tough in your build. Tough has a base of 15% S/L RES, so 3-slotted with even-level DamRes SO’s, it provides 23.63% S/L RES. Tough has a high endurance cost, tho (0.5/s as of I5), so you may want to consider adding a slot for EndRdx if you find slotting EndRdx in your attacks isn’t sufficient.

Stamina – I’ll always recommend Stamina somewhere between lvl 20 and 24. You can certainly do without it, but you’re life will be a lot easier with it.

Health – I would recommend slotting Health. In combination with Dull Pain, this will take your regen rate to a point where you can ignore a decent amount of incoming damage, at least during the times Dull Pain is active.

[I]Hasten[/I] – With ED, you can no longer have perma-Hasten. I expect this will result in many folk eliminating it from their build. Hasten still has some value, but it becomes situational, for example against foes that can slow your recharge rate.

[I]Weave[/I] – Weave provides positional DEF. As a result, it does not stack with Invincibility and Tough Hide. Because of this, there’s really very little reason to take it as it will only help in situations where Invinc and Tough don’t already apply, for example against Psionic attacks.

Air Superiority – Fire Melee notably lacks a status effect power, i.e. a power that disorients, stuns, knockdowns, or otherwise prevents a foe from fighting for a short time. If you're interested in flying as a travel power, consider AS as a prerequisite. It has a very high probability of knocking down a foe. Personally, i just don't like AS for some odd reason, so i'd recommend you try it on Test for a bit before you commit to it.

Tips for the new Tanker
==================================================

Build Strategies:
For goodness sake, take this build advice with a grain of salt! I will try to provide some broad strategies applicable to different playstyles, but my advice is necessarily influenced by my personal views of the I5 Inv/Fire Tanker. You may certainly find my advice doesn't meet your individual needs, but hopefully some of this will be useful anyway.

Overall Strategy
With the advent of I5, the importance of various powers in the Invulnerability primary shifted a bit and with ED, it shifted some more. It is easy to divide the available powers into three broad tiers, with the top tier including the most useful powers in the set and the bottom tier covering the most optional. These tiers are the basis for all of my build strategies, regardless of their individual goals.

Top tier Powers
Primary: Invincibility and Temporary Invulnerability should be first on your list for taking and slotting. TI is still the strongest S/L RES power and Invinc is now the best tool in your Primary for protection. The more you slot Invinc, the fewer foes you need in melee range to floor villain accuracy.
Secondary: Fire Sword Circle and Combustion should be first on your list for 6-slotted attacks. AoE attacks are the specialty of Fire Melee and these two are the best in the set.

Middle tier Powers
Primary: Now it gets trickier ... powers you probably want to take, but slotting is more controversial: Unyielding, Dull Pain, Tough, Tough Hide, and Health. Most of these powers have been weakened by ED. The newcomer is Tough, since you cannot cap S/L RES without taking and three-slotting it. Tough is certainly not required, but I believe ED does move it into the middle tier.
Secondary: Greater Fire Sword and Incinerate are attacks you will probably want to have and to slot heavily. In the later levels, having high-damage single target attacks becomes important, both for taking out individual threats among groups of foes (like that non-S/L damage-dealing boss crowded among the eight minions you have in melee range) and for tanking massive threats like AV's and monsters.

Bottom tier
Primary: Resist Energies, RPD, and Resist Elements. You can probably survive without these depending on your play style. If you're a defensive player, you probably want to take them, but you may choose not to slot them.
As mentioned before, you will need three-slotted RPD to get to the S/L cap. However, since you can get pretty good S/L RES with TI, UY, and Tough, some folk may find they don’t have room in their build for it.
With ED, taking and three-slotting REn and REl may become more popular, since it only costs four additional slots.
Secondary: You have to take Scorch, and its a decent attack among all the mandatory tanker secondary attacks, but i would certainly classify it with Fire Sword and Breath of Fire as the most optional attacks in the set.

You may note that Unstoppable, Taunt, and Build Up are not included in the tiers. None of these three powers is necessary, but they do tend to be a source of constant debate among tanks. I have seen builds and playstyles that rely heavily on them and have likewise seen those that do not.

Build Goals
When you start developing a build, you should have an overall strategy and a collection of goals to support that strategy.

Consider things like, how much RES do you want to have and when? Is it important for you to get the most defense out of your build early or to start out with enough offense to have a full attack chain by lvl 12? How heavily do you want to rely on Invincibility for overall defense? Do you plan to play mostly with teams and use a team-focused build or do you need a build for solo-only play or somewhere in between.

Your answers to all these questions affect how you build your hero. Let’s look at some specifics.

]Early RES Aggressive Build
If you start building with the strategy of taking and slotting all your RES powers as early as possible, you might end up with a build like this:
---------------------------------------------
Exported from Ver: 1.5.8.0 of the CoH Hero Builder
---------------------------------------------
01) --> Temp Invulnerability==> DmgRes(1) DmgRes(3) DmgRes(5)
01) --> Scorch==> Acc(1) Rechg(7) Dmg(7) Rechg(11) Dmg(11) Dmg(13)
02) --> Resist Physical Damage==> DmgRes(2) DmgRes(3) DmgRes(5)
04) --> Taunt==> Taunt(4)
06) --> Boxing==> Empty(6)
08) --> Unyielding==> DmgRes(8) DmgRes(9) DmgRes(9)
10) --> Swift==> Run(10)
12) --> Hover==> Fly(12) Fly(13)
14) --> Fly==> EndRdx(14) Fly(15) Fly(15) Fly(21)
16) --> Tough==> DmgRes(16) DmgRes(17) DmgRes(17)
18) --> Invincibility==> DefBuf(18) DefBuf(19) DefBuf(19)
20) --> Health==> Heal(20) Heal(21)
22) --> Stamina==> EndRec(22) EndRec(23) EndRec(23)
24) --> Resist Elements==> DmgRes(24) DmgRes(25) DmgRes(25)
26) --> Resist Energies==> DmgRes(26) DmgRes(27) DmgRes(27)
---------------------------------------------
01) --> Sprint==> Empty(1)
01) --> Brawl==> Empty(1)
01) --> Gauntlet==> Empty(1)
02) --> Rest==> Empty(2)
---------------------------------------------

This build ends up with 55.25% S/L RES by lvl 12 (if you can afford the DO’s) and jumps to 74.75% S/L RES at lvl 17 with the addition of Tough. It also gains 13% non-SL RES at lvl 12 (with DO’s). When SO’s become available at lvl 22, this build reaches 97% S/L and picks up 27% F/C/T RES at lvl 25 and 27% En/Neg RES at lvl 27 with REl and REn, respectively.
As a consequence, however, Stamina gets pushed out to lvl 22 and the build is reduced to a single attack from its secondary for quite some time. The build also skips Dull Pain, which can be a useful survival tool in the early levels. Resist Elements and Energies are available sooner, but taking them would mean delaying a travel power or Stamina even longer. Even skipping Taunt at lvl 4 wouldn't bring them in sooner, since neither is available that early.
This may be an ideal build for a very team-centric tank who wants to grab aggro for her team as early as possible, but it does come at the cost of slower-paced solo-ability.

Early Moderate Build
Here's a nice moderate build:
---------------------------------------------
Exported from Ver: 1.6.2.0 of the CoH Hero Builder
---------------------------------------------
01) --> Temp Invulnerability==> DmgRes(1) DmgRes(3) DmgRes(5)
01) --> Scorch==> Acc(1) EndRdx(3) Dmg(7) Rechg(13)
02) --> Fire Sword==> Acc(2) EndRdx(5) Dmg(7) Rechg(13)
04) --> Taunt==> Rechg(4)
06) --> Swift==> Run(6)
08) --> Unyielding==> DmgRes(8) DmgRes(9) DmgRes(9)
10) --> Resist Physical Damage==> DmgRes(10) DmgRes(11) DmgRes(11)
12) --> Hover==> Fly(12)
14) --> Fly==> Fly(14) Fly(15) Fly(15)
16) --> Health==> Heal(16) Heal(17) Heal(17)
18) --> Invincibility==> DefBuf(18) DefBuf(19) DefBuf(19)
20) --> Stamina==> EndRec(20) EndRec(21) EndRec(21)
22) --> Dull Pain==> Rechg(22) Rechg(23) Rechg(23)
24) --> Combustion==> EndRdx(24) Acc(25) Dmg(25) Rechg(27) Dmg(27)
26) --> Build Up==> Rechg(26)
---------------------------------------------
01) --> Sprint==> Empty(1)
01) --> Brawl==> Empty(1)
01) --> Gauntlet==> Empty(1)
02) --> Rest==> Empty(2)
---------------------------------------------

This build also ends up with 55.25% S/L RES by lvl 12 (if you can afford the DO’s) and 13% non-SL RES at lvl 12 (with DO’s), but it stays there until SO's are available. When SO’s become available at lvl 22, this build reaches 66.7% S/L and 15.7% F/C/T RES. These are slightly weaker, but certainly the S/L RES is still strong enough for most situations.
As a consequence, however, Stamina gets pushed out to lvl 22 and the build is reduced to a single attack from its secondary for quite some time. The build also skips Dull Pain, which can be a useful survival tool in the early levels. This may be an ideal build for a very team-centric tank who wants to grab aggro for her team as early as possible, but it does come at the cost of slower-paced solo-ability.

Offense-oriented Build
If you want to go the route of offense as the best defense, you might put together a build like:
---------------------------------------------
Exported from Ver: 1.6.2.0 of the CoH Hero Builder
---------------------------------------------
01) --> Temp Invulnerability==> DmgRes(1) DmgRes(3) DmgRes(5)
01) --> Scorch==> Acc(1) Dmg(3) Rechg(7) Dmg(9) EndRdx(13) Dmg(17)
02) --> Fire Sword==> Acc(2) Dmg(5) Rechg(7) Dmg(9) EndRdx(15) Dmg(19)
04) --> Dull Pain==> Rechg(4) Rechg(23) Rechg(25)
06) --> Swift==> Run(6)
08) --> Unyielding==> DmgRes(8)
10) --> Combustion==> EndRdx(10) Acc(11) Dmg(11) Dmg(13) Dmg(15) Rechg(17)
12) --> Hover==> Fly(12)
14) --> Fly==> EndRdx(14)
16) --> Health==> Heal(16) Heal(23) Heal(25)
18) --> Invincibility==> DefBuf(18) DefBuf(19) DefBuf(21) TH_Buf(27)
20) --> Stamina==> EndRec(20) EndRec(21) EndRec(27)
22) --> Build Up==> Rechg(22)
24) --> Taunt==> Rechg(24)
26) --> Resist Energies==> DmgRes(26)
---------------------------------------------
01) --> Sprint==> Empty(1)
01) --> Brawl==> Empty(1)
01) --> Gauntlet==> Empty(1)
02) --> Rest==> Empty(2)
---------------------------------------------

With DO's at level 12, this build reaches 44.5% S/L RES and 11% non-S/L RES. With SO's at level 22, this build reach 53.1% S/L, 12% non-SO, and then jumps to 21% En/Neg when it picks up Ren at 26. In exchange for slightly worse defense, it gets three six-slotted attacks and BuildUp, and gets them a few levels earlier than the moderate build.

Current 50 Build
Finally, here's an example build i'm testing with as a prespective build for my lvl 50 Inv/Fire:
---------------------------------------------
Exported from Ver: 1.6.2.0 of the CoH Hero Builder
---------------------------------------------
01) --> Temp Invulnerability==> DmgRes(1) DmgRes(3) DmgRes(5)
01) --> Scorch==> EndRdx(1) Acc(3) Dmg(5) Rechg(7) Dmg(9) Dmg(13)
02) --> Dull Pain==> Rechg(2) Rechg(7) Rechg(9) Rechg(13) Heal(37) Heal(45)
04) --> Taunt==> Rechg(4) Rechg(46)
06) --> Swift==> Run(6)
08) --> Unyielding==> DmgRes(8) DmgRes(11) DmgRes(11)
10) --> Boxing==> Empty(10)
12) --> Hover==> Fly(12) Fly(45) Fly(46) Fly(46)
14) --> Fly==> EndRdx(14) Fly(15) Fly(15) Fly(37)
16) --> Tough==> DmgRes(16) DmgRes(17) DmgRes(17) EndRdx(21)
18) --> Invincibility==> DefBuf(18) DefBuf(19) DefBuf(19) TH_Buf(37) Taunt(43) TH_Buf(45)
20) --> Health==> Heal(20) Heal(21) Heal(23)
22) --> Stamina==> EndRec(22) EndRec(23) EndRec(25)
24) --> Resist Physical Damage==> DmgRes(24) DmgRes(25) DmgRes(27)
26) --> Combustion==> EndRdx(26) Acc(27) Dmg(29) Dmg(29) Rechg(34) Taunt(34)
28) --> Tough Hide==> DefBuf(28) DefBuf(36) DefBuf(40)
30) --> Fire Sword Circle==> EndRdx(30) Acc(31) Dmg(31) Dmg(31) Rechg(33) Taunt(34)
32) --> Resist Energies==> DmgRes(32) DmgRes(33) DmgRes(33)
35) --> Resist Elements==> DmgRes(35) DmgRes(36) DmgRes(36)
38) --> Incinerate==> EndRdx(38) Acc(39) Dmg(39) Dmg(39) Rechg(40) Dmg(40)
41) --> Greater Fire Sword==> EndRdx(41) Acc(42) Dmg(42) Dmg(42) Rechg(43) Dmg(43)
44) --> Build Up==> Rechg(44)
47) --> Unstoppable==> DmgRes(47)
---------------------------------------------
01) --> Sprint==> Empty(1)
01) --> Brawl==> Empty(1)
01) --> Gauntlet==> Empty(1)
02) --> Rest==> Empty(2)
---------------------------------------------

Basic Info for Beginners
If you’re new to being a Tank or have previously shied away from CoH game mechanics, now may be the time to learn a few new things. Issue 5 brings a series of changes to Inv/Fire and its difficult to fully appreciate them without a basic understanding of how things work in the game.

RES and DEF
==================================================
There are two basic types of defense in CoH: Resistance (RES) and Defense (DEF).

Resistance affects the damage you take from an attack. If you have resistance and an attack against you is successful, it will do less damage. For example, say you have 25% RES to Fire attacks and a Demon shoots you with fire for 100 points of damage. That 100 point attack will only do 75 points of damage to you.

An important thing to note about Resistance is its specificity to damage type. There are eight types of basic damage: Smashing, Lethal, Fire, Cold, Energy, Negative Energy, Toxic and Psi. The Invulnerability powers typically provide RES to only one or two damage types, which makes it important to have a general feel for how resistant you are to each type and to gain some experience in what type of damage certain foes specialize in.

Tankers cannot have more than 90% RES to any type of damage. Even if your powers give you an accumulated RES over 90%, you will always take 10% of the damage an attack does. For example, say you have 110% RES to Fire and a Demon shoots you for 100 points of damage. That attack will still do 10 points of damage to you even though you have 110% RES. This is known as the resistance cap. For Kheldians, the RES cap is 80% and for all other AT’s its 75%.

In addition to the eight types of basic damage, there are two unusual types you may be interested in. Untyped damage is damage that cannot be resisted. There aren’t many things that can do Untyped Damage in the game. Hamidon is one prime example. Nictus damage is a special kind of damage only Kheldians experience. You won’t need to be concerned with Nictus damage as an Inv Tank.

On the other side of the coin is Defense. Defense affects how successful a foe will be in hitting you. If you aren’t hit, it doesn’t matter how much RES you have, you won’t take any damage. Of course, on the other hand, if you are hit, but don’t have any RES, you’ll take full damage. Different types of foes have a different base chance of hitting you. Your DEF is subtracted from that chance resulting in a final chance of being hit. For example, if you have a 15% DEF bonus and a villain has a base 50% accuracy, the villain will have a 35% chance to hit you.

No matter how much DEF you have, a foe will always have a 5% chance of hitting you. This is known as the to-hit floor. For example, if you have 65% DEF and you’re being attacked by a villain with a 50% chance of hitting you, the villain will still have a 5% chance to hit you.

DEF is either [I]typed[/I] or [I]positional[/I]. Typed DEF only applies to a specific type of damage, for example 25% DEF to Fire damage. Positional DEF depends on whether the attack is a melee attack or a ranged attack. Anglican has an excellent Guide to Defense that you can check for all the details.

Tankers tend to have typed DEF. For example, Invincibility is DEF to S/L/F/C/En/Neg/T (note Psi is missing). For attacks that have multiple types, only the highest typed DEF counts. So, if you have 10% DEF to Fire and 20% DEF to Lethal and a villain attacks you with Fire Sword (mixed-type Lethal and Fire), you get 20% DEF to the whole attack, i.e. both the Fire and Lethal components.

As an Inv Tanker, your primary powers are focused on providing you with RES and DEF. Its important to understand the basic concepts behind these defenses so you can make choices on how you select and slot your powers.

==================================================
Appendix One Issue 5 Summary
I left this here as a reference for folk who have been gone since Issue 4, to help them understand what has changed in the recent past. For the full details, please check Buffy's Guide reference above. The following list summarizes the major changes affecting Inv/Fire tanks in Issue 5: