Crits, Speeds, & Bleeds (Fury of the Faithful, Immolation Grenade, Blazing Piety)
 Zealot Build - Warhammer 40k: Darktide 

Still WIP, but I've really been fine-tuning this build now that I've been playing damnation/auric regularly.

Still untested on auric maelstrom or havoc, but I've found this to be a fun, reliable way to mow down virtually all threats the game throws at you while maintaining survivability and helping teammates when they're downed or surrounded by mobs.

-Since we're building around Flesh Tearer and Scourge, damage can be our dump stat for the knife. You'll be doing enough bleeds and crits to make up for it.

-High mobility with the knife and good stamina allows you to stay mobile, rapidly clearing armor, ranged enemies, and specialists. This build has high survivability, so as long as you're dodging away like you're supposed to, you should be fine. 

-Single armored enemies can be easily dispatched with a heavy knife blow to the back of the head, utilizing Backstabber for increased damage. Thanks to the knife's insane mobility, it's not difficult to kite around big, slow enemies. Large groups of Crushers, Bulwarks, and Maulers get a flame grenade and a generous smattering of bolter shots. A bolter with high crit chance+carapace+unyielding+ Deadly Accurate means it'll take only a few shots to drop em, especially if you ADS for a sec or two to stack up Surgical .

That goes for monstrosities as well. If you're feeling brave dive in with the knife and stack up loads of bleeds. If you need to be more cautious, hang back and plug away with your bolter, ensuring you're stacking up Surgical + Deadly Accurate for extra big chunk damage.

-On hordes, throw the Immolation Grenade to clear off the chaff, then mulch anything that remains with the knife.

-Frequent crits will fuel the Scourge + Flesh Tearer cycle VERY frequently (like every 2-3 hits when Blazing Piety is up, which should be up virtually the entire mission thanks to Fury Rising and Righteous Warrior).

-Use Fury of the Faithful to guarantee crit/bleed and regen toughness in a pinch; two uses means you've almost always got one on hand when needed, and Invocation of Death paired with near constant crits melts FotF downtime.

-Spam doges to proc Duellist and Second Wind when in melee.

Go forth in great speed and righteous fury, dispensing the Emperor's mercy upon the heretics!