Or another bard. Basically a mezzer to keep the damn NPC from killing himself, or aggroing God-knows-who while you fight.
Of course, need a mem-wiper also, worked easy with our bard doing it, even without Fade.
Might not hurt to throw a shaman in there, just for the extra slowing power. Overall though, isn't very hard.
Another trick you can do, have a couple of people running *just ahead* of the NPC, making SURE they're following his path.
Aggro the mobs ahead of the path and kill them, makes the trip a little smoother. That way, once the NPC dude stops in an empty room, you *know* you're about to get jumped.
Mobs generally pop in the middle of the room (unless it's changed), and if you're a caster, they'll scoot for you first...I did this with my necro, and with my friend's cleric...and each time we were 1st targets for some reason, even though I was standing far away from the NPC, so have melee ready to taunt.
Like others said, last mob is lots of HP, not sure how hard he hits since I'm a necro ;)