In a recent PTR build, several trash abilities were updated or changed completely in the Underrot Dungeon. This drastically lowers interrupt requirements and makes it easier for players to disrupt many impactful enemy abilities.
Underrot Cast Behavior ChangesThe cast behavior of several abilities were adjusted in Underrot, generally making abilities easier to disrupt and less frequent. (Listed cast frequency numbers were approximated from log data and may not be exact.)
Befouled SpiritHarrowing Despair No longer recasts when stopped by non-interrupt abilities Bloodsworn DefilerShadow Bolt Volley Cast frequency changed from 15s to 26s Summon Spirit Drain Totem No longer interruptible Chosen Blood MatronWarcry Cast frequency changed from 16s to 25s Devout Blood PriestDark Reconstitution No longer recasts when stopped by non-interrupt abilities Diseased LasherDecaying Mind No longer recasts when stopped by non-interrupt abilities Cast frequency changed from 16s to 27s Faceless CorruptorAbyssal Reach Cast frequency changed from 12s to 17s Maddening Gaze Cast frequency changed from 12s to 17s Fallen DeathspeakerRaise Dead Ability removed Wicked Assault Ability added Wicked Frenzy Cast frequency changed from 15s to 25s Now interruptible No longer recasts when stopped by non-interrupt abilities Fanatical HeadhunterBarbed Spear Cast frequency changed from 6s to 10s No longer recasts when stopped by non-interrupt abilities Hooked Snare No longer recasts when stopped by non-interrupt abilities Feral BloodswarmerSonic Screech Cast frequency changed from 13s to 24s No longer recasts when stopped by non-interrupt abilities Thirst For Blood Cast frequency changed from 15s to 20s Grotesque HorrorDark Echoes Ability added Read more on wowhead.com