PsyCrit
 Psyker Build - Warhammer 40k: Darktide 

For a crit based melee focused Psyker

Combat Blade VI, has more cleaving light attacks in the combo, and heavy 1/2 both cleave as well. Tac Axe II, or Rashad work well here with BM and Shred.
Perks:

• Crit chance - we want max possible criticals possible since we have a ton of extra finesse and we also get toughness and move speed from them. Flak is okay, maniac is mostly for ragers and mutants as everything else dies in one critical hit.
• Elites - Helps to take out the most troublesome enemies like ragers, maulers and ogryn.

Blessings:

• Flesh Tearer - With our huge crit chance (72.5%) you will normally get max bleed stacks in 2 hits and that will kill most enemies.
• Riposte - not listed on the site so I can't select it, but it is what we want.

Trauma Staff - Great for dealing with melee elite enemies that can cause issues for combat blade. Can also refill toughness on our guaranteed crits.
Perks:

• Flak - Can be swapped out for elite with little issue.
• Maniac - Helps to kill almost all specials and Dreg ragers - can also be swapped for elite.

Blessings:

• Rending - Since we are not taking Uncanny on Combat blade in favor of more crits, this will be our best way to deal with carapace, and it will also increase the damage we deal to all enemies if we swap weapons. 
• Warp Flurry - Helps to cast faster, not a lot of other good options of staff. Focused channeling is fine.

During ult, and at 100% peril you will have a max of 55% TDR, and your base line is 39% at 0 peril with ult - making for a consistently tanky Psyker. Mettle is your primary means of regenerating toughness, and since it is on crit you can regen it off hordes and single targets, with melee and ranged. Lights will cleave 2 mob enemies typically for 10% toughness, heavies can cleave 5~ mob enemies on crits for 25% toughness per heavy (making is similar to Ogryn talents just way more versatile in this build while also giving move speed)

True Aim guarantees a crit on Trauma secondary, if you hit 20 enemies (not that hard in Auric) that totally refills your toughness bar - all enemies in the 8m~ blast radius will count, not just the 2.2m Epicenter (the primary white circle), great for fast toughness refills specially with how fast True Aim is stacked.

Disrupt Destiny will refresh on any damage done to marked targets (only gain stacks on kill) Bleed will refresh Disrupt and bleed kills will give stacks. The damage increase from Disrupt destiny increases Bleed damage as well.
I find Lingering Influence to be more consistent than Perfectionism - definitely take Cruel Fortune if you want Perfectionism.

Gaze Also increases our Dot Damage, give movespeed (hilarious on knife) TDR crit chance and finesse. Massive damage increases for Blade, and makes us much tougher. Should be used pretty much on CD - and since we have a ton of cooldown it should be used very often.
Can trade Warp Speed for Force damage talents like Perfect Timing and Malefic Momentumif you want to increase Trauma efficiency.

We only take Smite because we need it for Psykinetic's Aura, and Brain Rupture would remove an easy access TDR node for something we will almost never use specially since we can't effectively use Kinetic Resonance so it is incredibly slow.