I've beaten it with The Legendary Dark Knight so far. I like how both the sky and floor change every 1000 floors; helps to allievate the monotony of battling in a static arena.
Edit: Just beat it with Super Nelo Angelo.
"Pluto shall come on the promised date and separate heaven and earth. One with black wings of treachery shall come and stand in Pluto's way." - DMC1
Currently Playing: "Tom Clancy's SplinterCell: Chaos Theory" - PS2