The Fabled Gruplinort  

Very definitely doable with a small group. I was factioning in seb with my shaman and when I went around a corner he was right there to greet me with some pain. I slowed him, clicked spiritual channelling, and spammed heals on myself while I let DoTs eat at him. Got some adds which made channeling difficult. I ended up dying when he was at 0% and had 2 fresh DoTs on him that guaranteed he would would join me in death within a few seconds. Needless to say, I was not a happy camper. Anyways, here's some info on him...

He has plenty of hp. I'm not good at guessing hp off of damage, but I'd say 100k hp or more. I know he took an 800 DoT tick and was at 99%. He was partially slowable, and not very resistant but there were resists. He was white con, so level 70. He hit me for around 1500 max. I have 1600ish AC and maxed Archetype, PoP, and OoW mitigation AAs. Checking on shielding... hmm, I don't see any regular shielding items. Wow, I suck. Anyways the most important thing to note about this fight is that he's a wizard (or something along those lines). He spends a great deal of his time casting. I resisted everything he cast so his spells aren't much to fear. However once he runs out of mana, LOOK OUT. Since he has nothing better to do than melee his dps skyrockets. If you don't have a good tank you're going to want to put him down before he runs out of mana. Last but not least, he summons. Like that's a big surprise...