Assuming it's a custom idea:
The ring perspective is really awkward. It should be flattened, maybe with some custom text thrown onto it. It also doesn't blend well with everything, perhaps a darkening/contrast.
The cage seems very small, perhaps you could extend the height of it? You could also consider throwing some blood stains on it
The lights on top look really bad. Gradient/Color loss badly, you should take care of those and consider animating them.
Some signs or camera flashes from the crowd is always a nice effect.
Also, you should seperate the deltas more so the ring moves seperately from the audience. Also, I personally usually go with a vertical follow of .94 and floor tension 60 with tension 40, however yours's not wrong, but it looks awkward for certain characters.
Also, all that black space is very bland and boring. You should add more to those areas. Also maybe you could consider changing the bgm to the stage name? So for us unorganized people it's easier to find, lol.
Also, it's not a HUGE deal however your cage sprite can still be cropped to remove some uneccessary pink.