They might have changed something here, because I ran into this guy last night in a regular dungeon. It was a 4 person dungeon, all of us were lvl 65, and the dungeon setting was normal. He dropped the Slippers of Dark Mana, and he was not a difficult kill at all.
Our group consisted of a 65 Warrior, 65 Rogue, and 2 65 druids.
Youre thinking of the Enchanted Ice Mass. Its a lvl 62 named mob that spawns in the 65 normal dungeons. The Enchanted Ice Form only spawns in the Hard ones
He is from lvl 65 setting on Hard. You never see him any other way. Hits for around 900-1000 and has average amount of HP. Took a few mins to whittle him down; just a straight melee fight and his AC is up there so that cuts into your DPS output. He has nothing particular on magic resist and bard pacify worked on him just fine. Hes unmezzable same as all named mobs and has same aggro radius. Slow stuck fine on him