huh? next you will say there's only one Yoshi and what you said made no sense. You are awarded zero points
I'm sorry. If that made absolutely no sense to you I believe you have poor English comprehension or did not even attempt to read everything I said.
Mewtwo is a bad example for this situation. I presented a better example: Link.
Would you put Toon Link's Wind Waker pajamas on Adult Link? No. They're two different versions of the same character, with totally different designs. Link's Wind Waker pajamas are a part of Toon Link's world, and belong to the character of Toon Link.
Similarly, Twilight Princess Ganondorf and Ocarina of Time Ganondorf are two different versions of the same character, with totally different designs. The Phantom Ganon mask from Ocarina of Time is in no way a part of the Twilight Princess universe. It is a part of the Ocarina of Time universe and belongs to Ocarina of Time Ganondorf.
It is a part of a completely different designed world with a fairly different art style. If someone wanted to fit the mask onto Twilight Princess Ganondorf's fat face, they could, and they could throw it up on Brawl Vault along with the thousands of other ugly textures and edits that don't look professional, but it would not meet the standards set forth for Project M.
I don't know how much more I can break this down for you. I've probably already used too many words.