Why does Jhin have an interaction with Yasuo?

i thought that Jhin would have killed yasuo's master and made the scene looks like yasuo did it, but apparently it's not possible since jhin was in jail during the noxian invasion until the end of the war (and apparently yasuo's master was killed during the war and not after it ended)

so why does he have an interaction with yasuo? ""It's fun to kill a man, to take all that he had, and could ever have."