The Spirit Realm

Stairs camp is the best place to fight him by far, you get a corner, you can have healers duck down the steps and avoid the ae while still staying in heal range and you don't have to worry bout repops, cept the one that spawns really close to the steps. With 1 group on his hatelist his dps isn't much worse then a normal RS named I'd say, but it's been a while. I would bring atleast 2 capable healers, the AE's are pretty rough and he does ramp, so be sure to set that properly. Also be sure to Levi yourself, he has an AE knockback, tho you may want to ignore that on your tank since he will be in the corner anyway, and 1 time I did have some weird summon/knockback while floating and got pushed over the back edge of the steps, it was no good =/.