Blood
It would be a nice effect if the blood (since there seems to be quite a bit of it) would stick the toris as the fight progressed, the same effect as the floor, just on the fighters instead. If this were added, it should probably be optional since people might not want their textures to be obscured by gore. Now, I have no clue about the technological side of this, so it could very well be impossible or at least impractical. I just think it would be a cool addition to see sometime in the future.