goon burst
 Psyker Build - Warhammer 40k: Darktide 

Use boom staff to deal with hordes, and to knock down Crushers and Ragers.

Use dueling sword to dodge sideways during combat when possible, effectively repositioning during combat. Anticipation talent makes its duration absolutely silly, and agile allows you to gain distance indeterminately to cast the rest of the kit in the event you are solo. It should also be used to finish off specials after you push them.

Use Brain Burst against specials - deploy a shield in gateways and it will not only guard that entrance but it will boost your brain burst speed and cheapen it, so it can be used offensively. Psionics will make it even faster, allowing you to safely pop whole gunner emplacements from your goon cave.

Ideally, don't dump nor stock the 2 shields unless you really need to - it will push off whole conga lines of poxbursters and mutants which can be helpful to keep the team integrity during maelstorm/havoc. With Brain burst's kinetic flayer, it can also randomly kill things by just sitting there. You'll basically always want a shield deployed to up your brain blast being charged, as Psykinetic's Aura, Seer's Presence, and Curios reduce the cooldown quite a bit.

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Crystaline Will is optional - you may pick any freebie from the tree instead of it (Wildfire or Perfect Timing in particular) if you think you can handle the peril generation. I do not think it is bad, specially since if a wound is about to become corrupted (let's say 99% purple), then blowing up your brain will merely push it to (100%). doing a small AoE of 500 damage and resetting your peril. It can be very useful in a pinch, though ideally you don't want to trigger this - Consider it training wheels. 

Same goes for the +1 Wound curio, though ideally you don't want to be getting hit at all. There is no real use for Stamina in this build as the Boom staff should be pushing everything off you.