Allrounder Zealot
 Zealot Build - Warhammer 40k: Darktide 

Curios doesn't really matter other than having 3x stam regen. I personally run 1 wound 2 toughness but you can run other things. 

Annointed in Blood gives you important breakpoints on 1hs for bombers/flamers, as well as snipers.
Revolver Headshots on Crushers allow you to dispatch individual ones quickly, but you'll find that just spamming their body has poor results (especially with no crits).
For Reavers, you can 2hs them if you wait for Surgical, or RNG one crit.

Heavy attacks from Heavy sword 1 shots Muties and Hounds. 
Use heavy sword's special attack into Heavy attack vs Crushers. 

Use Immolation grenades -> Chorus stunlock to wipe away mixed hordes (especially strong vs bulwark mixed hordes), revives, and DPS bosses. This build takes advantage of the fact Darktide has no armored bosses in the game yet. This strat will be ineffective once there are some, but currently in patch 13, this is a great way to melt bosses. 

You can also utilize a dodge slide -> chorus to get close up to gunner squads. Releasing the chorus at the start of a pulse (I recommend letting chorus channel for at least 3s total) gives you ample time to start charging up heavy attacks and get close and personal with the gunners. The invulnerability + extra toughness will also last a while into combat. Similarly to Shroudfield & Chastise, be careful of biting off more than you can chew.