Who are some characters that you feel are pretty much the same deal? Their creations don't have to overlap (ex. how two different characters have been created simply because the writers weren't allowed to use John Constantine), but if they are interlinked in their creations or there have been comics that have addressed their similarities, feel free to share

I for one have always been curious as to how come Vandal Savage and General Immortus have never interracted (at least to my knowledge). Two evil immortals with similar enough deals of commanding armies and having positions of power over history, it's curious to me that I've never seen them meet each other and address their similarities