Simply give him orochi's FB where oni's were discriminated and pushed out of wano and Kaido came to take revenge and that would be good. I am baffled how oda fumbled with Kaido's story. Orochi does not adds anything to the story.
he had the other intangibles other villains had like planning out schemes and backhanded plans etc
felt that part of kaido was lacking.
said it before and will say it again
his strength was truly the highlight of his character. we never got to see his intellect , his leadership, in essence his competence without having to swing his club. Truly what makes characters like crocodile or doffy even though they are weaker more complete villains. would have been better if oda just wrapped all those things in one villain rather than those wasted panels on orochi.