Psyker
This weapon Blocks both Melee and Ranged attacks. Additionally, Block Cost is reduced by 22.5-30%.
12-24% Rending on Enemy Weak Spot Hit for 3.5s. Stacks 5 times.
5-8% Strength for every 10% of magazine spent during continuous fire. Stacks 5 times.
Gain between 3.5-5% and 14-20% Critical Chance based on current level of peril.
EDIT (December 13th 2024): I changed the Unstable Power blessing on the Deimos sword to Uncanny Strike thanks to Tanner's video about this build. I had no idea that the Rending from Uncanny Strike applied retroactively to every instance of already-extant soulblaze DoT. That is ridiculous and I have no idea why it works that way, but it's incredible for melting thick packs of armoured enemies. I highly recommend checking out Tanner's video about the meta for this build, and you can find it here: https://youtu.be/c81jkUhzEOs
EDIT (April 12th 2025): After trying this build on high level Havoc, I recommend dropping Blaze Away on the staff for Penetrating Flame. That seems to be necessary for how ridiculous the enemy resistances become. Keep Warp Nexus because despite the crit resistance of enemies, the crits still apply extra soulblaze DoTs as well as proc your survival and damage talents. I don't enjoy high level Havoc because I hate fake difficulty, so I have little else to recommend for this build in regards to Havoc.
The goal of this build is to be an all-rounder that pumps out tremendous amounts of damage to everything as well as slow/stagger incoming ragers & horde all while being tanky enough to handle about anything when things get rough.
With this build you want to stay at high peril at all times. Use Brain Rupture to keep your peril high between engagements and use it at the beginning of a fight to pop a rager, gunner, or specialist to spike your peril so you can dump a max Creeping Flames Venting Shriek into the mixed horde before going hard with the Purgatus/Inferno staff.
Why stay at high peril? Because this build hinges upon using Venting Shriek to apply 6 soulblaze stacks to everything in the huge 30-35 meter cone (which affects things even through hard walls) as often as possible. You only need 85% (or there abouts) to apply max stacks, so you don't have to be at max peril for this purpose. Using Venting Shriek effectively and often relies on two things. First, make sure to use In Fire Reborn instead of Psychic Vampire, because that choice + Psykinetic's Aura + 12% CDR from curios means you'll be able to Shriek every 8-12 seconds in heavy combat, sometimes even faster (often on Aurics I can Shriek again almost immediately after using it). A trick to Shrieking often as possible is to watch the healthbars of the specials & elites in the horde and Shriek when you see many of them are about to die, that keeps your Warp Siphon charges up to further reduce cooldown on your Shriek. Proper usage of this and the Purgatus/Inferno staff will easily max out your soulblaze DoTs on the OpFor in seconds (which leads to triple-digit DoT damage per tick).
Speaking of the staff, remember to use left click and right click correctly. Use the left click to hammer packs of ragers and mixed hordes of ragers, shotgunners, and regular guys to keep them staggered, and in between you can hose them all with a partially charged right click to max out the soulblaze DoT. The Blaze Away blessing is easy to keep maxed by spamming right click as fast as you can; sending out little 1-2 second pulses keeps the blessing buff maxed and allows better tactical usage and application of the DoT. You should use this to rapidly max out the DoT on bosses as well (soulblaze DoT + force sword stabs when available are a better contribution to boss damage than trying to land a few Brain Ruptures).
Obviously the build isn't great against bosses, but since you can rapidly max out soulblaze stacks on bosses it will contribute more than you might think (especially if bosses live longer than 5 seconds). If you're good at the boss "dances" you can land powerful hits on them with the force sword heavy attacks to add to your DoT damage.
The Deimos sword is great for handling bulwarks, crushers, and maulers, which is the only thing the staff + Shriek can't rapidly melt via soulblaze. I use this sword for 3 things. First, I empower it before a strike if I absolutely have to lockdown an armoured enemy (like if a crusher is bearing down on an ally and I need to stop it more than kill it, works on mutants too like side-stepping and sticking it with a revved up chain weapon). Next, I use the second heavy attack in the combo to land powerful lancing blows on armoured enemy heads to deal spike damage and knock them down. This allows me to effectively "dance" with packs of maulers and crushers while rather quickly killing them, especially if I have already loaded them up with soulblaze DoTs. Finally, I use Deflector + Block Efficiency to allow me to be able to block-tank bosses and lots of melee enemies at once when I need to, and if I need to cross an open area or pick up a downed ally it's nice to be able to block ranged fire.
Talent Options: If you don't like the short period of rapid Brain Rupture from Kinetic Resonance, feel free to drop this. It's totally optional and you don't need it, I just enjoy using it for rapidly popping gunners and specials when the time is right. You could trade Kinetic Resonance for Kinetic Deflection to keep your peril high and effectively double your Block Efficiency when things get rough. Another decent option would be picking up Quietude or one of the +15 Toughness nodes if you're having trouble with chip damage. You should avoid nodes which reduce peril because once you're comfortable with this build those nodes only become a hindrance to optimal output.
Equipment Options: The melee weapon is up to you. I only use the Deimos sword for the specialised applications I outline earlier, but if that doesn't work for you then feel free to use whatever you're comfortable with to keep you alive. My other recommendation would be the Dueling Sword since it serves a similar role and will help keep you alive with an even better dodge & better damage against crushers than the Deimos. In regards to curio perks, the CDR is mandatory for this build, but the others are up to you. I prefer stamina regen + sprint efficiency since I utilise the movement boost from Mettle to rapidly sprint/slide around the combat zone for optimal AoE placement of my staff & Shriek cones as well as making sure I'm near the front lines (it costs a lot of stamina to keep up with Zealots haha); I also block a lot so I run block efficiency on every one of my builds. Good curio options if you don't like these would be bonus toughness or revive speed. I consider all choices for the Purgatus/Inferno staff to be mandatory for this build.