Auric Maelstrom - Strike Psyker
Build for Darktide

This one is simple, use the Voidstrike... thats the build.
 

Dump stat for the Voidstrike is the Quell Speed, trust me you won't need it.

Dump stat for the Knife is First Target

Once you get the Warp Flurry blessing to max stacks which can be achieved very quickly, you're sending out fully charged attacks every second, and if you're aiming roughly for the head, you're 1-2 tapping pretty much all elites, plus dealing massive amounts of stagger.

The Voidstrike also has insane levels of Penetration, so treat it like a plasmagun, apart from when shooting crushers or maulers, at which point the impact landing on them will be enough to stagger them and everyone around them anyway, so you can finish them off for free.

Weak spot hits on the Voidstrike deal insane amounts of damage, lets play into that.

When dealing weak spot hits, you are playing heavily into the Ebb and Flow of Psyker. With both Quietude and Warp Expenditure, you are gaining toughness both when you gain and quell peril, as you are constantly firing the staff, you are constantly gaining peril, and using the talents "Battle Meditation", "By Crack of Bone" and the blessing "Transfer Peril", you are quelling peril much faster, and gaining more toughness on weakspot hits/kills. Taking extra ranged weakspot hit damage amplifies this, making the usual Ebb and Flow on Psyker much more potent here than even some of the best Psyker builds out there. Also with Soulstealer, you're gaining toughness here too. Everything happens, all the time. 

I've been a Psyker main for a long time, and Voidstrike had it's hayday and was nerfed, however, it's back and while it's damage is now significantly more tuned than it was back then, it's a much better and more well-rounded build now. I would even say this is the best Psyker build out there right now.