Not every One Piece antagonist needs a deep flashback; Kaido's narrative sufficed to establish him as a compelling villain.

Kaido has openly been labeled to be the strongest pirate in One Piece on many occasions, but, there might be one person even stronger than him, and that person is none other than Shanks.

One Piece's Wano Arc doesn't hold back in showing us the reality of being a pirate, especially when Kaido's ruthlessness ...