Traditional Culture Encyclopedia - Photography and portraiture - Why can Black Beard, One Piece, have two abilities?

Why can Black Beard, One Piece, have two abilities?

As far as I know, it's because of the "D" in the name. It is said that everyone with a "D" has two hearts, and one heart hides a devil's fruit. Therefore, two hearts can contain two demons. However, if the control is not good, two demons may fight. You can watch the episode of CP9 again. (But few people can control two hearts. Black beard is a wonderful flower. )