No, you are right, but how much xp do you get when you kill him?
Well, I reloaded an old save game to find out. The amount of experience you get depends on the level of your character, so this isn't a fixed number probably, but with the 47th level character I killed him with just now I got 140430 XP, 12766 of which was added because of maxed out wisdom.
No Experience Bomb, but pretty nice! <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />
Never had an XP Bomb with any of the Black Ring members either... The chances are quite slim of course.