Mouse continued his habit of staying quiet and focused before the fight, but he couldn't help but notice his rival. The boy was laughing and joking with his sponsor, his smile was even kind behind that monstrosity of a body and his inability to feel pain. He was a child, that's what Mouse saw, it's possible that if they had met in the same area they could have been friends, or so Mouse thought.
It's not that he regretted being there, but if he could avoid it he wouldn't kill his rival, he would defeat him, he would try to make him go quickly, but something had changed in him since his fight with Boots, he would do his best to win, but he wouldn't sell his soul for it, he wouldn't end up being like those bullies he used to face to protect poor weak boys.
He remembered Balloon Head and Rabbit, he remembered why he fought, why he survived, so as not to see anyone suffer because of bullies. He wouldn't be a bully.