Emollious in T2 is dumb simple.
Pull all the trash and AOE it down. Emo saunters in. park him in the green aura - if you can, you can wiggle your tank aroudn so emo is in the aura, tank isnt and your melee arent, otherwise just emo+tank in green. Ignore the moving to other auras. He'll go immune for a bit because of that but who cares. At 80% two mobs spawn - an East guy and a West guy. "supposed" to be balanced. No penalty for not. They dont even hit you (iirc). healer/tanks stay on emo, send your dps and a couple shamans to kill the east or west guy first. whatever makes you happy. then kill the other guy.
Then go stand on Emo and beat him till he coughs up loot. Everybody needs lev. but thats the mechanics. it's reallllllly simple.
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I'd arguably say Ring-Around-The-Rat is infinitely more difficult (at least, in era) with its aggro lock mechanics, adds, aes and the like. Grummus isnt bad, but hurdle is Stem The Tide. Otherwise grummus is a full burn dps while kiting 2 of his frandz, and not standing in the huge green auras of bad.
Grannus had a bunch of run-around and do-stuff mechanics: tank boss, 'cure' under him (optional, but cheeve), run to a room and kill a portal thing (do it til portal dies), then ccing adds in the room that do stuff, like the flinging unicorns and dispel(?) and silence(?) npcs. it's an annoying fight.
Damsel of Decay was T2 and super mechanical and may be difficult if you werent good at mechanical fights. in T3, High Bokon Boromas was somewhat mechanical, but enough DPS will brute force the fight. Efefctively a boss with timed adds and also iirc % based and a couple different phases.
If you have request for everything, Emollious, Fear/Hate, and Maybe Boromas are probably your easiest fights?