Staff Bolt Scrier
 Psyker Build - Warhammer 40k: Darktide 

This build specializes in spamming staff bolts (i.e. staff primary attack) with high crit rate to scale both direct damage and the extra projectile proc from Surge blessing. Crit chance on the staff is around 90% when all buffs are active and peril is maxed, and is around 50% with no buffs and low peril. Landing weakspots hits will significantly increase DPS against most targets, except against maulers and plasma gunners who have carapace helmets and flak body armor. Staff secondary attack can be used to open bulwark shields and damage crushers from range.

I chose the Mk VI knife for its high mobility and DPS against crushers and bosses. Other good melee options include the force greatsword, Illisi or Deimos force sword, duelling sword, or Devil's Claw sword.

Curios are mostly personal preference. You could drop the +3 stamina curio for another +17% toughness if you want, but I recommend swapping a skill point to take Warp Ghost if you go that route.

Blitz is personal preference. I took Assail for killing horde trash faster. Smite is probably the "best" option in terms of utility for the build, but I hate Smite so I only really consider the other two. Brain Rupture is largely redundant with the staff spam, but it can be useful for sniping specialists.

I recommend Prescience aura over Seer's Presence because crit chance is a massive damage multiplier for this build and Scrier's Gaze already has a short cooldown. Seer's Presence is generally more valuable to teammates though, so feel free to use Seer's Presence instead.

Channeled Force isn't super useful since you won't want to bother full-charging secondary attacks on the staff that often, but it's better than the alternatives for pathing. Empyric Shock is good for single-target damage, especially against bosses.

If you don't like the reduced toughness recovery on Empyric Resolve, you can swap that out for something else. You will likely have less Scrier's Gaze uptime without Empyric Resolve though.