The Mortis Infiltrator - Stealth Shock Build
 Veteran Build - Warhammer 40k: Darktide 

An off-meta Stealth Vet for tricky situations - "Best way to not get killed is to not get seen"

A Veteran of the Mortis Regiments, Guardsmen trained not as soldiers but as instruments!

• Mortis Pattern Knife for mixed hordes and general threats. A killing tool suited to a regiment whose entire reputation was built on being seen only once, when it mattered. Solid bleed damage through Mercy Killer and Serrated Blade means most elites only need two hits to the head. Also, a solid armour piercer with Uncanny Strike paired with those bleeds, makes this blade a very versatile choice with no need for backstabs. 
• The Mortis Pattern Bolter, This mark is meant to be used up close and personal with these blessings. Dealing death into packs of elites, armour, or bosses, not for single ranged combat. Through this weapon is primarily used in tandem with stealth. Withering Fire is here to help with punching through those large groups effectively.
• Stealth ability is used to get close to gunners to knife, for objectives and revives. Can keep one spare for an emergency thanks to Overwatch. When faced with a mortis-level threat, gameplay looks like this: go stealth to stack damage from Close Quarters Killzone Marksman and Infiltrate itself, tag to Focus Target! on a boss or group of crushers, then mag dump with your bolter, aiming for weak spots. This is the whole doctrine in miniature: get close unseen, mark the kill, and only then let the noise start.
• Shredder Nades, while not the most powerful, can be tossed quickly and not break stealth if thrown underhanded, very good to mix into a horde about to hit your team before you get to boltering. 

WARNING — stick close to the team with Infiltrate; you are no Zealot, a Mortis operative's whole edge is the element of surprise. lose that, and you're just a man with a combat knife.