Amazing piece of music :D
The battle theme somewhat reminds of Seymour from Final Fantasy X who was a constant pain in the ass all the way to the last encounter with him where he tries to destroy everything and whatnot. This actually is quite well composed and quite dark, sinister, and lovely at the same time. Also kind of have a feel like you either have to run or fight.
Pick up your weapons and fight the evil thingy Akuma!!
Drums sounded quite heavy and retributive which is quite good for a piece like this. It also notable switches with the music as well going from heavy to moderate and then heavy again, nice.
The keyboard sounded right on as well and very dark and sinister, good for a final boss battle with something that apparently tries to destroy everything outright as well. Nice work on that part.
Chorus sounded pretty nice especially with the deep male voice that keeps coming in on the heavy parts, sweet.
Overall this is some pretty nice ear candy for a fitting final boss theme and it successfully loops as well, very nice job working on this piece of music.