With the changes to Slayer’s Blades I no longer get the 15 -resist reduction from Mark of Dreeg component. So does the Noxious Poison Bomb -resist reduction stack with Vulnerability? Trying to decide if I should switch to Venom-tipped Ammo even tho Dreegs infinite Gaze does more sheet DPS for my character. Obviously if they stack then the answer is Yes.
They should. However, the resist reduction from NPB won’t stack with that from Acid Spray.
yeah i don’t use acid spray and Nine Confirmed that Noxious Power Bomb and Vulnerability definitely do stack. But thank you for also letting me know 
I’ve been looking at the following resist reduction for a poison build:
Manticor
Dreegs component
Poison bomb component
Vulnerability
Night’s Chill
Malediction
Which of these stack? What combination will achieve the maximum poison resist reduction? Are there any that I’m missing?
http://www.grimdawn.com/forums/showthread.php?p=251347#post251347
If these are still true, Vulnerability and Night’s Chill stack and also stack with the highest reduction from [Manticore, Dreegs component, Poison bomb, Malediction]. So if you use all of those, only the reduce resist from Vulnerability, Night’s Chill and Malediction will add together. Manticore, Dreegs component, and Poison bomb will do nothing.
Actually there is a special case for -resist reduction when they’re coming from the same source (in this case, your weapon).
Plaguebearer’s and Mark of Dreeg will stack, for example. Malediction probably will, too. Double Mark of Dreeg also stacks, unless they changed that.
AFAIK, that probably won’t work when DWing or using 1H + Shield. However it might work with 1H + Focus. But in the case of 1H + Focus it might be better to slot Blessed Steel in the focus instead because Sacred Strike gives 30 extra resist reduction instead of MoD’s 15. The downside to that is that SS is a cooldown skill which means it will not recharge when weapon swapped. It also only works against a single target.
On another note, I just want to emphasize how great the “of the Abyss” suffix is for non-Soldier, non-physical builds that do at least 100% weapon damage at most every 3 seconds. General percent resist reduction is quite rare but quite useful for such opponents as Herald of the Flame. Plus it also has a solid chance of general percent damage reduction, another extremely useful debuff.
Now that I’ve said that, Crate will probably nerf it.
I think you are over-valuing the resist reduction on “of the Abyss” unless your enemy has a substantial amount of either postive or negative resists after all flat resist reductions are applied it actually does rather little. You need to reach either +100 resist or -100 resist for the reduction to be on par with Plaguebearer’s suffix for instance.
You know, this section of Raiyaz’s resist reduction post really bothers me:
[/li]Shouldn’t #2 be last?
I think I wasn’t reading that post carefully enough and only focused on that list, which may be incorrect. In the case that general percent resist reduction really does come last, I guess I did overstate the importance of “of the Abyss” WRT to resist reduction. BUT it’s still really good in terms of damage reduction. And those builds able to access many different sources of flat resist reduction such as pyromancer (fire), conjurer (vitality), and witch hunter (poison + cold) would still benefit significantly.