Brain Bursty Kal
 Psyker Build - Warhammer 40k: Darktide 

perks, blessings and curios are listed in order of priority from top to bottom

I do not take Kinetic Flayer since it consumes valuable stacks of Empowered Psionics, chances are the 10% brain rupture will be wasted on some random poxwalker anyway.

with Empowered Psionics, your Brain Rupture can 1 shot kill almost all specials and elites, with the exception of mutants, ogryns, and maulers which require 2 Brain Ruptures. using a empowered BR to kill a elite immediately gives you back your EP charge, which means you can drop a shield, and clear an entire room full of elite gunners and specials faster than any other class barring an Executioner's Stance Veteran with perfect aim.

purgatus staff is chosen because its the best short range mixed horde clear weapon in the game, with the exception of zealot's flamer. important breakpoint is 76% Burn for 15 stacks, and as close to 80% Cloud Radius as possible for a whopping 16m fire range. Damage % is a dump stat and is practically worthless. Focused Channelling means you can stand your ground and fire into the horde without getting interrupted by walkers or shooters. Crits apply 2 burn stacks instead of 1 which is why Warp Nexus is chosen as the second blessing. Alternative staff is trauma or voidstrike but your melee game needs to be good.

alternatively, taking the double charge on your shield ability synergises with Kinetic Resonance, but i find that when you pop a massive safety dome on the floor allies tend to rush into it for the safety and toughness regen, guaranteeing x4 team coherency. I have yet to encounter a team wipe on cata+ when all 4 members are in the big blue ball at once. 

i like deflector and stam/BCR to give psyker very strong melee and ranged tanking abilities, and to be able to hold block and literally walk into gunfire to revive teammates. however a very strong alternative is to replace deflector with Bloodthirsty, and replacing the perks with Infested>Flak for a more offensive melee setup

i find it essential on cata+ for psyker to have 2x +15 toughness nodes for a total of 170-180 toughness to prevent sniper 1 shots from full hp, but if your awareness is high enough that that never happens to you, feel free to remove those 2 points and reallocate to Kinetic Deflection so you can tank daemonhost for funsies

feel free to remove the +1 wound curio and replace with toughness/+3stam, but i find that in cata+ if everyone runs 2 wounds baseline as per the established meta, healing station heals have to go to the grey screen players as a priority since their next down is a death. having a +1 curio means you can go down once and still leave healing station charges for those 2 wound players who are already on grey screen (which funnily enough happens very often to players who follow the 0 wound meta).