A friend of mine, who has written/is writing one of the most epic Mewtwo fanfics ever to exist, suggested a few sketches to go along with the hardcover version, once he finishes the series and gets around to getting it printed at his campus's printing press.

Here is one scene from the Crossing of the Paths, where Mewtwo is talking with a Gerudo by the name of Kalana. (Yes, it's a Pokemon/Zelda crossover at first, and then branches out later.)