I know pyris ignite counts as individual stacks for soul renderer. Are there any other debuffs I can exploit this way
It wont count for Soul Renderer but Zephyr is individual buffs too. Gora's Poison Thorns would count if you are fighting fast attackers like Slicers or Flayers. Iceburst Brew (the slowing potion) makes your attacks apply individual debuffs much like Pyris too. Technicalllly things like Shiv, Stuns, or Nessa's Rejuvenating Flames count but arent very easily stacked. Some monsters apply multiple different debuffs too the like Tizik Lightning Rod & Overload so even though the stacks arent individual it still nets some easy bonuses.