I've never played the Thousand Year Door, (I do own the game, but I don't own a Gamecube or an Original Wii. I did own the two, but The Wii got replaced by a new black Wii and then that got replaced by the Wii U, and the Gamecube got stolen) But I watched a YouTube video of the fight, and while he does have some minor similarities to Wario both in design and attacks, they are in no way the same character. (Nintendo would had made it more obvious and a bigger deal, if this was the case.)