Doffy was a seinen villain in a shonen manga. He was smart, calculating, manipulative, charismatic. When it came to his relationship with Viola, Oda even said there were a lot of "adult themed" stuff he couldn't mention because it was a kid's manga.
Kaido probably appeals to a younger demographic who likes more upfront DBZ-style confrontations.
Kaido probably appeals to a younger demographic who likes more upfront DBZ-style confrontations.