Teamplayer Knife Zealot
 Zealot Build - Warhammer 40k: Darktide 

Attacks:

For Knife MK III:

+ Knife Light Strikes for crowd control and "Uncanny Strikes" stacks.

+ Knife Fast punch strikes (special action key + light strike) for carapace armor.

+ Knife Push stab for ragers and bosses (and other dangerous melees).

+ Knife Heavy Strikes as sprint attacks.

+ Blades of faith and revolver for distant enemies.

Differences for Knife MK VI:

+ Push stabs for carapace armor and ragers.

+ MK VI has a much nicer crowd control and push stab, but is a tad slower.

It really comes down to personal preference if you want to use MK IV or MK III. The selected blessings stay the same. Damage against unyielding is also great, but i prefer flak because of it's broader application. Crit hit is fantastic, because it also buffs your defensive because of "Enduring Faith".

Always aim for weakspot even on maulers and crushers (rending buff)

Gameplay: 

+ Dodging is important as it refills your thoughness and reduces incoming damage (25%).

+ And of course dodging gives you "Momentum" stacks while in fight. With persistent dodging you will have 15 stacks almost always.

+ If not in fight you want to run to refill your 15 Stacks of Momentum.

+ With dangerous melee enemies try attacking, then dodging backwards and then attacking again. Rinse repeat.

+ Sprinting counts as dodging, but I recommend constant dodging nontheless.

+ Stay within coherency as much as possible as your aura "Benediction" grants 15% dmg reduction to you and your team, which is just fantastic.

+ Basically your mindset should be to play being so fast to your teams advantage. You can use it to quickly disengange and re-engage where your team needs you. If you use it to run off to engange distance enemies you are devoiding your team of the benediction aura and endager yourself being pinned or to busy to disengange. I recommend rather using revolver and blades of faith to deal with gunners and other ranged problems. Of course if the situation allows it your speed is great to quickly collect materials and such.

+ Crit Hits are important as they give you crazy damage reduction (50%).

+ To hit enemies hard and fast use the Mk III knives special action key (the punch) and then a light strike right after. Do that consecutively. Takes a bit of getting the hang of but in no time you can spam that chain of attacks and it does incredible damage. With MK VI knife it's a bit wonky so I rather recommend push stabs.

+ Blade of faith take some training to get used to because only headshots are useful, but when you get the hang of it, then they are extremly useful. In the beginning rather aim twice, shot once. 

+ Always aim a little over their head, the game is quite forgiving if you hit the general head area.

+ Blade of faith benefits from the weapon you have currently equipped. I always switch to knife because it gives you rending stacks. With 5 stacks of rending you can three shot a crusher.

+ Make sure to always reload your revolver in moments in between action.

+ Make sure "Until Death" is recharged before doing anything risky.

+ When you sprint and then do a heavy strike you run even faster.

+ I recommend to change sprinting to toggle instead of being pressed in the settings.

+ I recommend to change the settings, so you dodge instead of jump if there is no directional input.

Ability:

+ If you want to use it for damage, use it for big targets. Use it so you backstab them.

+ It can be used to get out of tight spots, but keep in mind you cannot move through enemies, so if you are surrounded and the last person standing, they will just stop attacking you but still block your escape.

+ If a player is downed you can shroud yourself and quickly rezz them (make sure they are not in immediate danger to go down again (surrounded by 20 maulers or in the middle of a fire lake).

+ It's also great to do objectives like the hacking or scanning while being shrouded if the pressure is high and doesn't go down until the objective is done. You can quickly do the objective while everyone else focus on clearing, but beware to assess if that is actually helping in that moment.

Generally, but important nonetheless:

+ Freeing netted players and players with dogs on them have a priority. If you are not in immediate danger to be downed or pinned yourself you should always untangle the net, even before killing the responsible trapper, they have to reload before they can net you too. Just shoot the dogs with the revolver

+ When there are hounds around switch to knife, it feels counter intuitive first because you feel less armed with, but you can push them. If you hear the hound doing its pounce, even is he is behind you, just push. The push is 360° and goes much further than it looks like. You can reduce being pounced almost to zero.

+ If you hear the charging sound of a trapper, just dodge to the side, even if you don't see them. Doesn't always work but often enough.

+ Mutants, dodge them when they are one meter away. Usually in the direction of their weak arm, but if that way is obstructed double dodge in the other direction.

All of the above might change in the future due to updates or newly collected knowledge or brain damage.

Thank you for coming to my Ted Talk.