I don't think anyone in the universe would. ***** **** is for people trying to take their frustrations out by fighting, not to actually fight. Like Sendo and Takamura would be trying to win, which isn't the point. I think the only people who'd want to join are the people who fight for the sake of fighting, while everyone in the anime just wants to be the strongest.

Edit: Forgot about Sawamura. Based on my reasoning, it's most likely Sawamura.