Kai couldn't help but be intrigued by the woman's offer. It would be nice to have a village to call home again, the opportunity to shed the title of Missing-Nin. But the idea of fighting this woman simply to prove his strength, that gave him pause. This woman had done nothing to him or the other Jinchuriki. 

At that moment...Kai remembered what Konoha had done to him. The way they had made his family "disappear" overnight due to his questions. The way they had tried to have him killed and the way they had left him for dead in the middle of a forest and he nodded his head.

"I accept your offer." Kai said. "I would rather not fight you but if that is what has to be done to prove myself then I will."