Warp tankhammer
 Psyker Build - Warhammer 40k: Darktide 

This build works better in the higher difficulties as there is way more to kill and keep the perils and stacks high.

The overall aim of this build is to increase damage as much as possible by increasing perils by any means while at the same time passively managing perils in order to keep replenishing toughness in every situation. Because of this scrier's gaze is ideal, it constantly builds peril which also builds damage on its own scale and unstable power for a total of 60% more power..... totals will be included further down.

Compared to the usual psyker builds that are best focused on lower perils and safer options like standing in the bubble shield this build creates its own ranged protection by both active and passive abilities increasing crit chance to auto dodge ranged attacks while you're hacking through the hoards up close.

I also prefer to take lingering influence over perfectionism because 10% damage would be great but for 4 seconds there's no guarantee you'll reach 25 stacks wherehaving those stacks hang around for 10 seconds gives more opportunity to score the kills on marked targets.  

Damage - scriers gaze 10% base + 30% based on perils

Unstable power - up to 20% based on perils

Warp rider - up to 20% based on perils

Disrupt destiny - up to 15% based on stacks

For a total of up to 95% damage bonus 

Crit chance

Warp nexus - up to 20% based on perils

Scrier's gaze - 20%

Crit chance boost - 5%

For a total of 25% crit chance in melee and 45% crit chance with the staff.

For this build ive gone for the Deimos force sword because of the high damage and better precision for weak spot hits. Also because the charged attack is far better at dealing with anything with armour than the illisi force sword is. Without any damage bonus stacks or scriers gaze a deimos sword can 1 shot anything up to ogrn size enemies but still maintains the speed and precision to allow total effectiveness against every enemy.

Using the trauma staff in my opinion is ttHe better option because personally I've found it to have a higher base crit chance allowing more opportunity to get kills to replenish toughness and quell perils which keeps you alive and keeps scrier's gaze active.

In this build i have used smite as my blitz because the utility of hoard control and knock down when you release the charged attack gives you and your team some breathing space when things get a bit overwhelming and also generates perils which increases damage done and starts the chain.

Possible alternatives would be;

Assail instead of smite to try and snipe lit targets to get those stacks built up.

Mind in motion instead of malefic momentum which would sacrifice some damage in place of not being slowed by quelling although the idea of the build is to quell by killing.

Precognition in place of reality anchor, adding finesse damage to scriers gaze can really help take down some of the bigger enemies although perils build up will be faster so you would need to be a lot more aggressive which isn't always advised for a psyker.

And finally perfectionism in place of lingering influence, may be more useful when fighting hoards as there is more chance of the lit target being closer to you and making 25 stacks more achievable.