>>532224515
This was how the Shrouded affix worked. Season 4 of Shadowlands. There was hidden, disguised Dreadlords scattered throughout the dungeon. Killing them gave your party a permanent buff (and you chose what the buff was).
You'd re-route your dungeons to optimize trash% with Dreadlord buffs for optimization.

It was fucking kino and I want it back so bad.