Price's '100% Crit' Blazing Chorus Knife
 Zealot Build - Warhammer 40k: Darktide 

It took me a bit to long to realize that Combat Knife can hit 100% crit with specifically Zealot. Turns out, Scourge (30%), Blazing Piety (25%), Base character crit chance (5%), Riposte (20%), Combat Blade innate crit bonus (15%), and a little melee crit chance perk (5%), all sums up to exactly 100%. 

This lets you spam whatever ability you want with infinite Invocation of Death uptime (along with all your other crit effects like Enduring Faith), and this is the build goes about spamming Chorus. An 'in between' compared to the two other variants I've put up, gets to have Second Wind, doesn't get to have extra damage from the top middle tree. To that end, I focused more on support to an extent, and threw on a Lasgun just cause free crits are funny on it and for the sake for variety. See my other '100% crit' builds if you want a Flammer or a Boltgun that will help you do the job. But mainly, just knife everything you see, spam chorus for more damage and golden hp, and lasgun anything that tries to shoot at you (using it to proc Enduring Faith at range while getting toughness with second wind). 

Very usable, though you don't feel IoD quite as much with Chorus, but it still lets you throw it out quite often.