SpittingTrashcan

A bit late to the party, but:

Singular They? In my English? It's more likely than you think.

Also, read Language Log.

Hm. So I had a post but it got eaten. I'll try to summarize.

1) Air Sup is okay, but CJ is very cheap, actually less EPS, doesn't reduce your DPE or DPS, protects against Immobilize, can be slotted with KB prot, and is a prereq for a KB prot power.

2) End costs are not nearly as bad as they're being made out to be - my DA runs 7 toggles all the time and does not have end problems.

3) Def is irrelevant. DA functioned fine before high def was even achievable.

4) OG by itself will not stun any LTs; it's mag 2. Hence the synergy with /Stone and Fault. But even only stunning minions (and providing enough stun to stack mag 5 onto a LT/boss in one shot from Stun, TF, Bonesmasher, or ET), it's so cheap that there's no reason not to take and run it.

It's worth drawing particular attention to DA's useful exotic properties. It has no damage type mitigation gaps - it's somewhat weaker against Energy, but Dark Regen works against anything. It has fear protection and end drain resistance. It has a functional combat rez - if you do go down, you come back invincible and just about anything near you will be stunned. It has a damage aura, a very cheap stun aura, and an (admittedly very expensive) fear aura. It's a quirky set, but decent in its fundamentals.

Resistance resists resistable resistance debuffs. Resistance does not resist unresistable resistance debuffs. Until recently, Longbow Nullifier Sonic Grenades were unresistable resistance debuffs. Now they are resistable resistance debuffs.

Clear as mud!

Edited to add: The reason the Fire shields do not mention resisting resistance debuffs is that this is not a separate property of the power, unlike defense debuff resistance. It's possible to have one value for defense, and another for defense debuff resistance. It is not possible to have two different values for resistance and resistance debuff resistance, because they are the same number internally.

DA/EM should work. The HP cost of Oppresive Gloom is laughably tiny; the HP cost of ET is no big deal either, considering that DA has the single most powerful heal in the game. DA is somewhat heavy on end use, but not impossibly so, and choosing your toggles carefully will help with that (Oppressive Gloom is quite light on end cost, for one).

There are other alternatives you might want to consider, though. DA/Stone would be more costly, but also a much better AoE stunner. DA/Fire would combine good survivability with good AoE damage, letting you plop down in the middle of big spawns and burn them down in safety. DA/Ice would be low on damage, but give a huge variety of mez and debuff powers: stun, fear, knockdown, hold, sleep, slow/-rech, -tohit...

HEATs are badly designed. This produces both their low average performance and their high peak performance: if you are fortunate or well-informed and take the powers that were randomly created stupidly good instead of stupidly bad, and learn how to get the most use out of them, you're awesome! If you are not so lucky, you will be in pain.

VEATs are well designed. This produces their good overall performance in anyone's hands: their powers range from pretty good all the way to pretty good, so there are fewer wrong ways to build a VEAT, and a greater degree of build flexibility. Where HEATs are designed so that they can be built to switch from job to job, doing each one pretty well, VEATs are designed so they can be built toward one or more specific jobs, and do that job really well. A VEAT can be one of several combinations of stalker, scrapper, blaster, defender, tank, and mastermind, and all of these build options are viable and playable solo or teamed.

To be crude:
VEATs are a bar of gold - take any piece, and you have gold.
HEATs are a cow pie with a diamond in it - unless you know what you're looking for, you're going to get poo.

I submit that both are playable, and both can be powerful, but one is clearly better designed - unless you feel that "good design" is synonymous with "difficult and inaccessible except to the persistent or well-informed." And if it is, I pray to god that you do not design anything I ever have to use.

I think Elec/DA would work, but not because of Elec's end return. Rather, any set that provides good AoE damage, particularly combined with mobility reduction (knockdown, in this case), works well with /DA.

/DA is expensive, but not as expensive as sometimes claimed. Theft of Essence in Dark Regen helps, as does choosing your toggles carefully. Oppressive Gloom has a remarkably low end cost for its effect.

It would, I think, have been more helpful if the OP had asked what particular build would be the least effective. Labeling an entire AT "useless" would be both wildly incorrect and extremely provocative.

If you want to make a character that contributes nothing, any AT will work. Just never, ever visit a trainer or slot enhancements, and you will be a dead weight.

If you want to make a character that is worse than useless, I recommend looking into powersets with lots of enhanceable KB powers. A petless /Storm or /FF MM would be both extremely fragile and have great disruptive potential.

One thing I could get behind is retention of costume piece unlocks on a reroll. Also, retention of badges that can no longer be earned. Then again, I think that both of those things should be account-wide anyway.

There is definitely an AT preferential treatment when it comes to passive mitigation. Melee ATs have superior passive mitigation by design - because they have to be in melee range, and lack active mitigation. If they didn't have "preferential" passive mitigation, they'd be unplayable.

Edited to add: I'm a little surprised that this had to be pointed out.

It took me about an hour of fiddling with spreadsheets and working out differentials to come to pretty much the same conclusion.

As to your first caveat, that resistance is hard to obtain, I can only point to the post title and add it to the list of interesting facts about defense and resistance. As to the second caveat... well, Brutes have a 90% resist cap, which changes the formula somewhat. I'm not sure where I'm going with this, honestly, but it's the only other place besides invuln where you get a survivability increase as the situation becomes more dire.

I agree with the above - of course, if the incremental bonus from RTTC is sufficient to beat the additional incoming damage, there is never a mitigation disincentive to throw another enemy on the pile. I still think that Invuln's property of offering, under certain circumstances, a mitigation incentive to take on additional enemies, does some weird things to risk evaluation.

On a not totally unrelated note, I'm working out the relationship between the amount of base resistance on a SR and the point where it starts being a survival strategy to hurt yourself...

Yes, on both Tanker and Scrapper. I'm giving the Tanker as much of a benefit from its superior mitigation modifier as I find reasonable; you could throw on Maneuvers and Hover if you want to find the absolute limit.

I think I'm not conveying my point successfully. Yes, it's possible to get an arbitrary fixed value of defense with or without Invincibility. What makes Invincibility uniquely potent, in my view, is that under certain circumstances its increasing mitigation outstrips the increasing threat from additional enemies. This is an extremely rare and valuable property for a power to have, and it's a property that both Tanker and Scrapper versions possess - while any fixed-value mitigation power, and even some scaling mitigation powers, do not. Hence the comparison to RTTC, which, although a scaling mitigation power, does not have this property - because existing regeneration does not increase the value of additional regeneration.

(Another power that does have this property: Eclipse - with the additional advantage that, as a click power, it does not thereafter diminish as the enemies that fueled it are defeated. This would make it quite thoroughly gamebreaking if it weren't for the fact that it supplies resistance rather than defense, and is attached to an AT with no mez resist in its most damaging modes and a resistance cap of 85%. Arguably, it still is, regardless.)

And my point is that the way defense scales means that the amount of defense you start from has a much greater effect on the potence of the Invince bonus than the actual amount of the bonus. That's what makes Invincibility potentially "incredibly potent." The contrast here is not between Scrapper and Tanker Invuln as much as it is between Invince and RTTC. In the case of RTTC, if n identical enemies are killing you, n+1 will kill you faster - the additional regeneration from RTTC will not ever start to outstrip the additional DPS. In the case of Invince, once a certain defense value has been reached, it becomes safer to fight more enemies than fewer - at least up to 10, or the softcap, whichever comes first. That's what makes Invince enormously potent, and it's a quality that varies between Scrappers and Tankers only in the amount of non-variable defense needed.

That difference is approximately 10.3%.* I leave it as an exercise to the reader to figure out how difficult this is to achieve.

* Assuming Invince, Tough Hide, and Weave slotted for 1.55x def, and unslotted CJ.

I don't have anything to say about Going Rogue until the day it goes live.