Rotation
It's really easy to play. Maintain Death Seal, Reaper Form and Wandering Spirits (on big packs or tough elites), then, hold down right click for Spirit Plague.
Ailments
With high cast speed, you'll maintain high stacks of Frailty, Poison, Damned, Slow, Spirit Plague, Plague, Possess (from Hungering Souls) and Marked For Death ailments from the build setup alone. Use Mad Alchemist's Ladle to stack damage and apply Electrify,Frailty, Shred Armour. You get 8%more spell damage per ailment!
Scaling Damage over Time & Poison Damage
Spirit Plague scales global poison and dot damage through Endless Decay 3/3 and Pestilence 3/3, acquiring an additional 468% damage over time at 13 stacks. Unsure if Rotten to the Core scales ailment damage. The "more" is certainly appealing, but it specifically says Spirit Plague in the tool tip. Without the poison tag, i am thinking it will not "more" the poison damage.
Wandering Spirits add another avenue for stacking Poison through ranged poison attacks Spectral Putrescence 1/1. Poison Spit
Reaper Form only adds 70% but adds duration to poison and increased global poison chance.
Hungering Souls adds 140% MORE damage over time against Possessed monsters with Inspired Hunger 5/5 and Descent Into Madness 5/5
Death Seal tops it off by increasing our damage by 330% from Corrupted Consciousness 5/5
Net damage increase is 868% from solely our abilities. Then, we get a 1.4x multiplier from Hungering Souls.
With Rotmind, DoT spells acquire base poison damage (doesn't explicitly change the tag, unfortunately). Base Damage scaling calculations for our abilities are great already. Additionally, it adds the benefit of our DoTs to scale off the added poison damage.
I've hit 100 stacks of Poison and easily maintain max stacks of every other ailment. With the amount of resistance penetration and damage resistance shred on the build and at the current gear of my build, DoT ticks are hitting upwards of 50k. There is plenty of room to grow the damage.
Skill Interaction for Hit Damage
Death Seal gains damage on Mortal Pulse through Cycle of Decay and Curdled Flesh while increasing global Poison Chance from Pustulent Presence up to 4% per missing health (264%). We don't need to (but can) build into poison chance because of this.
Wandering Spirits applies Poison from range through Spectral Putrescence and deals on hit poison damage. It benefits the most from Pustulent Presence
Hungering Souls is a DoT and DoT Against Possess'd Targets Buff. Pre 1.0, i'd use this for some damage, then decided that i'd rather just focus on scaling poison counts and removed the single soul setup. Now, we shoot a lot of souls, possess many monsters, and have better clear. With the addition of the Warlock support for curses and ailments, the damage for Poison is better than it was before the nerf and we don't need to supplement our damage more with the single target setup. We increase the frequency of free casting Hungering Souls with Death Seal.
Estimated DPS
The training dummy is in the Champion's Arena. Recent tests against it have seen peak 750k poison ticks and 200k plague ticks. Average ticks are between 250-400k poison and 70-100k plague ticks. This is a significant increase from 9.0.2.
I've been ticking on Orobus for 70-90k during burst, at 250-300 Corruption. Dodging mechanics and such it's ticking for about 20-40k. He dies reallly fast.
