Void Shard
 Psyker Build - Warhammer 40k: Darktide 

This build is EXCEPTIONAL sustained burst.. if you play it.. you need a really good melee/support hivescum, support vet or a TH zealot because it will probably get you killed.. when you get good with void builds.. you do insane burst and sustained at the same time and the game goes more nuts than it does to any other psyker build.. especially voidstrike builds that have disrupt destiny in them.. the AI goes fully mental without fail. so yeah you need someone who can pull you out of the bullshit because this build will get you extremely targetted. you will end up being the target of every wombo combo.. honestly as much as I love my voidstrike builds .. i also hate them.. the game is not kind to a good voidstriker. Honestly they gave anti threat to every class except the one that needs it.. If they gave an anti threat talent to Psyker.. Voidstrike builds would be the ones I would fit it into. It's just ridiculous how much the AI hates voidstrike..

So there are some options here.. The default is obviously Lingering Influence with Quick Shards.. I personally run Quick Shards with Perfectionism.. BUT, you have to have good enough aim and be quick enough with combo casting to ensure marked kills happen to maintain stacks.. also Lingering Influence is there for really competent teams.. on a good team you will find you struggle to maintain max stacks.. so even I run it in that case.. There is a third option here.. IF, you really want to maximize your combo casting and are more of a charge casting user.. and don't like to fuck around with assail use(it can be annoying to use properly.. everyone hates assail but if used right it's insane damage.. you need to constantly quick swap between bolting and assail chucking so that masses of targets are debuffed by empyric shock and so you trigger all your staff buffs while assail is in motion.. this is why it's so important that assail is buffed in builds in ways that will carry it further.. i.e. by finesse/crit or raw damage like Empowered Psionics).. anways..

IF you don't want to use assail for anything but easy stacks.. I suggest dropping Quick Shards, picking up Perfectionism and Cruel Fortune. This makes 25 stack maintenance really effortless and then your build can focus on pure staff casting for your output.