The Sanctified Shiv - Stealth Assassin Build
 Zealot Build - Warhammer 40k: Darktide 

Stealth Zealot Build - "Prayer may cleanse the soul, but pain cleanses the body."

The cult that raised him never once taught him to pray for mercy, only to deliver it, to whoever needed it the least...

• The Blessed Knife - For backstab and general horde clear through bleed stacks - Blinded by Blood, Flesh Tearer paired with the high crit rate allows for hive scum level DOT kills on mixed hordes. Lacerateis an option though i find it encorgaes me to not hit weakpoints which seems counterintuitive. No last rites, the tenets don't call for a witness. I generally only use heaves for the knife so Vicious Offering is an option but Enemies Within, Enemies Without is more reliable. Unfaltering also might seem tempting but heavies on the knife barely slow you so its not worth it. Uncanny Strike turns this into the perfect carapace killer from behind. 
• Pious Boltgun - Saved for the large packs and ugly fellas, toss a throwing knife mid animation to skip the lengthy swap. Puncture and Cavalcade gives rapid boss damage. Mainly for dire straits so use the blades for the occasional gunner. For when the quiet approach isn't enough, the transition to open violence is instant and you better have spare ammo! Wait in Line is an option through i find it safer just to approach those packs of gunners through stealth.  
• Last Rites" Stealth Stance - Master-Crafted Shroudfield and Time to Kill allow for easy one tap backstabs on lethal threats such as crushers and bulwarks, use for this, a get out of jail free card and to revive the team! Perfectionist I find overkill but is an option for you if not confident staying out of stealth for long 
• Blazing Piety -  For more consistent knife DOT.  Stalwart paired with Invigorating Revelation makes you a very safe even in a pack of Crushers, armed with nothing but a fancy shiv and conviction.