Psyker
12-24% Rending on Enemy Weak Spot Hit for 3.5s. Stacks 5 times.
5-8% Strength for 4.5s on Kill. Stacks 5 times.
-8.5--5.5% Charge Time on Chained Secondary Attack. Stacks 3 times.
Gain between 3.5-5% and 14-20% Critical Chance based on current level of peril.
This one is all about setting your enemies on fire.
Use charged attacks of Purgatus Staff for hordes - even mixed ones - to get max Warp Stacks in order to do more damage and less peril generation.
Use Brain Burst to kill enemies out of reach, works well after Venting Shriek as you can quickly cast is several times.
Venting Shriek is only there to burst more enemies with Soulblaze or to increase Brain Burst speed. Use it liberally, as you will regain your stacks quickly! Whenever a bigger horde comes, set them on fire for a few seconds, Shriek, watch them die, regain stacks, repeat.
Should not be needed as failsafe as Purgates is very forgiving there but can help in a pinch.
Deimos is there to dispatch whatever is not impressed by your flames - which will most likely only be Crushers, everything else burns just fine. ;) But those big boys will come to fear your charged heavy attacks to the face.
Alternatively: Use 2nd heavy attack (the stab) to one shot Mutants.
Not as versatile and strong as my other builds but gets the job done. You are very squishy though, so be careful. The Deimos does not have the best mobility and you are vulnerable when casting your flames.