Stealthy Meth-Head
 Zealot Build - Warhammer 40k: Darktide 

Build Basics:

The Knife:

Knife abuses the high crit rate and flesh-tearer to bleed out everything around you. Flesh-tearer works out better than lacerate for this since you're getting double the bleed stacks every time you crit, and between blazing piety and riposte, more than half your hits will be crits. Lacerate only works on non-weakspot hits, but you don't have that downside with flesh-tearer. You can aim for the head and still get the bleed stacks. With the additional damage from duelist, this means you'll get more than double the damage you would from going with lacerate. You can use the MK3 knife if you prefer, but the MK6 lets you cleave with heavies and the push attack spam is pretty good at deleting single targets. 

The Revolver:

The revolver is just there to delete carapace things. Maulers and Crushers go down pretty fast. Every time the revolver crits, you'll get 60% rending from hand-cannon, letting you smash through carapace. You already have high crit rate, but you can guarantee a crit by using shroudfield or aiming down sights for a couple seconds with surgical.

Throwing Knives:

Needed for the path to get all these nodes. I would prefer the immolation grenades, but can't make it without sacrificing something important. There's an interesting interaction with the knives and the revolver. They seem to take on the blessings from your gun, so you get the rending effect on crit and you can aim down sights with your revolver for a few seconds to guarantee a crit when the knife is thrown. This works to delete crushers, even if you're out of ammo for your revolver.

Key Nodes:

• Scorge - Free bleed stacks, higher crit chance
• Enduring Faith - Consistent 50% toughness damage reduction
• Duelist - Insane damage bonus
• Benediction - Additional 15% toughness damage reduction
• Invigorating Revelation - Gives back 40% toughness and adds yet another 20% damage reduction
• Sustained Assault - Free 20% bonus damage on knife spam
• Swift Certainty - Lets you ignore gunners while sprinting to cover (or any direction that isn't directly at them)
• Invocation of Death - With the crit rate from blazing piety, this will let you spam shroudfield
• Blazing Piety - 15% bonus crit chance, this is up most of the time, thanks to Fury Rising
• Fury Rising - Allows crits to count towards Blazing Piety activation
• Righteous Warrior - Brings Blazing Piety to a +25% crit chance. When combined with riposte and scourge, you're getting an additional 75% crit rate

Reasoning Behind Curios:

Sprint Efficiency and Stamina Regeneration just let you sprint all the time. This is nice for repositioning, but also lets you ignore gunners a lot of the time thanks to swift certainty. The block efficiency and tons of additional stamina are nice in general, and let you sprint around without worrying about not having enough stamina to block. Also, instead of taking "resist x damage" curios, you could just try to improve at avoiding those types of damage.