Its honestly supposed to be 3 levels above the level cap for that boss' expansion, so Nef would be technically lvl 63, Illidan 73, etc. I think tho with some of these "special" abilities like [spell=22993]Shadow Flame[/spell] which make the fights "unique" they make sure that while you can resist it some of the time, which I think is what happened to 3 of the 10 people last night, when it does hit you, it hurts. Once we all had [item]Onyxia Scale Cloak[/item]s on the fight was honestly a joke. Basically what happened tho was 7 people got hit with 20k damage plus a dot of some sort that ticked for 2k a sec and there was simply no way we could offset that with heals.