Aura of Decay does not appear to benefit from “more damage” modifiers from the Inspired Hunger node from Hungering Souls as well as the Plague Bearer’s Staff.
Inspired Hunger - “Directly casting Hungering Souls causes you to deal more damage over time against Possessed Enemies for 8 seconds. This effect does not stack.” (Up to 40% more at 5/5)
Plague Bearer’s Staff - 10-20% More Damage over Time against Enemies afflicted with Plague
Testing it out on the enemy training dummy, whenever I cast hungering souls which hits and applies Plague as well as possessing the dummy, my poison damage does not seem to increase as much as expected, going from 8000 per tick to 8300 per tick, and this is factoring in that the dummy will gain poison stacks and a stack of Plague when hit. I understand Aura of Decay still snapshots stats when activating but even when I try to have the Inspired Hunger buff up and Plague the dummy before activation, the damage numbers do not improve that much.