I personally think that it is likely for Kid to play an important role in the war against Kaido where he will help the Straw Hat alliance to take down the dubbed ‘immortal’ Yonko. I am 100% sure that he wants to seek revenge for what Kaido did to him, and his best option, by far, is to cooperate with Luffy and Law just like they did on Sabaody. Kid has also been portrayed as Luffy’s counterpart and potential rival when it comes to becoming the Pirate King, but I honestly think that this role is over. Luffy’s only real rival for that title is going to be Blackbeard. I think it is also likely that Kid is going to be on Luffy’s side during the potential final war against the World Government, together with most, if not all, of the other Supernovas.