I don't hate all Rap, but RPG battles are supposed to be epic.
Sometimes rapping lyrics can help, but it depends on the overall aesthetic and theme of the game as a whole, because without this final battle seeming so dark/hopeless and it being a remix of a theme heard all throughout the game, this music would not have worked well at all:
[Warning, spoilers for Persona 3 in the link ahead]
Sony bought Konami and will release a DDR game for the Nintendo 3DS. In this game, you set your 3DS on the floor and stomp on it till it no longer functions.