I wonder if Oda should have merged Shiki and Kaido as one character. It would explain his depression much more if he lost half his crew because of a storm, and when he went for a 1v1 fight against the Marines because he wanted to be the one to kill Roger, they teamed up on him, and didn't even give him the glory of a death, in a legendary battle, he ended up in impel down.
Also, Gold *Lion* and King of the Beasts