Psyker
-8.5--5.5% Charge Time on Chained Secondary Attack. Stacks 3 times.
Your Secondary Attack cannot be interrupted and loses 20-50% of Secondary Attack Movement Speed penalties.
This build is all around spraying warp fire on everyone and everything, setting it all ablaze, watching the galaxy burn!
You go for basically max chance to gain Warp Charges with the level 15 and 30 feats.
The cool thing about the Purgatus Staff is that it also applies Soulblaze like your ult. Since you pick Ascending Blaze (lvl 30 feat), all enemies that die to burn DOT have a 10% to give you a Warp Charge. Can easily get max stacks in seconds during big hordes - and you will be able to hold back a horde by yourself.
The more Warp Charges you have, the longer you can spray your staff (lvl 10 feat).
The more Warp Charges you have, the higher your damage output.
So basically all you do is spray into everything, regardless of whether it's trash or elites or specials. Set them all on fire. Do aim a bit downwards to give your frontline a chance to see something at least. ;)
Most enemies will be staggered (Maniacs and Crushers notwithstanding), all of them will burn. Many of them will grant you Warp Charges.
The burn DOT really starts to shine when you apply 4+ stacks. That's why we pick Warp Battery for level 25, as you using your ult will apply 6 stacks of Soulblaze on every enemy in front of you whilst also pushing them all back.
Then just charge your staff up fully and spray into whatever you want to see gone - this will easily erase even the toughest enemies as you just keep stacking burn DOT ontop of the 6 stacks.
Rinse, repeat. Use ult when overloading or whenever there's “enough” enemies while you got max Warp Charges. Like I said, even Crushers/Reapers will melt quickly if you use ult + more DOT.
Outside of that, they will take a while to get cooked well done, like the fat sacks of meat that they are.
You are quite vulnerable during the charging phase, so good positioning/dodging and awareness of incoming enemies is necessary if you want to survive.
Using Brainburst is optional but recommended if you want to help out the team with certain ranged enemies. The Purgatus Stuff should be your primary weapon, however.
You don't really need any specific blessings or perks, at least I haven't had a need for them so far. The ones I included are optional, heretics will burn and whither all the same.
Might be useful for Damnation diff but for Heresy and below, just burn them all. :)
Enjoy!