User blog comment:Fliu/Chapter 983: Yamato's Debut/@comment-4623405-20200621215144

Yamato seems like an ally as of right now. Luffy doesn't feel any hostility from him. Now in early one piece that wouldn't necessary have to mean something, but now with haki and being able to sense other peoples haki ... I think it's safe to assume that Yamato is an ally. But why? Maybe he wants to be free from  Kaido.

A possible theory: In Kaido's early appearance he was jumping off a sky island because he didn't want to live anymore. The current Kaido does not look like someone who actually wants to die. What if that is still his wish but he doesn't want to lose to someone on purpose. So Yamato is teaming up with his enemy to fulfill his fathers wish ...