Purgatus
 Psyker Build - Warhammer 40k: Darktide 

This is the glass cannon build with a focus on applying Soulblaze and dealing as much damage over time as possible. You will melt every horde with ease, just set them on fire with your staff and then shriek to finish the job.

Killing an elite applies Soulblaze, Venting Shriek applies Soulblaze, and anything that dies to the DOT causes it to spread to nearby enemies.

Brainburst is pretty essential here as you have no answer for distant enemies with the Purgatus staff, and you can't always rely on teammates to be around or have the right weapons.

As a capstone, I find Empowered Psionics is nice because you're able to rifle off faster Brainbursts when you need them. Warp Siphon is nice too, but costs more points so you'll end up losing probably a toughness node or two.

The flames will stun dogs making it pretty good for Hunting Grounds levels (It won't stun green dogs, so be careful).

Ragers and Crushers are scary. The only tool you have to stagger them is Venting Shriek. If it's just one or two enemies you can play the dodge game with your Dueling Sword, but if there's a pack your best bet is just to keep moving and burn the crap out of them - This is why my staff has Carapace and Maniac: Specifically for Ragers and Crushers.

This build takes a Stamina curio because you need to be more mobile. Without the shield to hide under, movement becomes essential.