Disclaimer: I own neither MHA nor Pokémon.

Prologue: Bored

Within this world, there exist a great number of creatures that have powers to both control, and manipulate element, and even time and space itself, a species known as Pokémon. But among all of these Pokémon, there is one that stands above the rest, due to her unique powers. The Pokémon I am referring to is the Legendary Pokémon that is known as Mew, the Phantom Pokémon.

Now what is special about the small cat like Pokémon is due to its genetic code, it can turn into any known Pokémon, from the simple Magikarp, to Arceus, the god of Pokémon. She is the most powerful Pokémon to ever of existed, able to play with space and time, like it is a game to her. But Mew has lived a long time, and has seen a great many things that many may never see. She has fought many battles, and has come out the victor no matter who the foe is. No one and nothing was a challenge to her.

To simply put, Mew is bored.

She has seen it all, and done it all. Nothing here was fun to her anymore, what to do, what to do.

Suddenly an idea came to the little cat Pokémon, if there was nothing in the universe for her to do anymore, find another one and play.

So Mew called forth some of her near infinite power, and turned the fabric of space and time malleable. She then created a hole in her universe, and gives a happy 'mew', and went through, and to find some new fun in whatever universe she may end up. Arceus help any poor universe that Mew pops out in.

Its playtime.