Lord of the distortion.
Naruto/Pokémon.
In this, for whatever reason, all of the legendary Pokémon except Arceus has died. This eventually leads to people in the elemental nations becoming the inheritors of the power, and duties of the legendary pokemon. And of course Naruto would become the new Giratina, hence the title. Now in this, a person must have some kind of connection to the legendary before they can become it, which means Naruto would have to have similarities to Giratina. Now im not sure about him actually being able to transform into giratina, but at the very least his appearance should change to match Giratina's color scheme. (like hair, eyes, etc)
Since Naruto will be spending most of his time in the distortion world, he'll be socially awkward, as he'll only have any real form of contact with a few people. But as Giratina, Naruto will be able to use any and every technique Giratina could use as a pokemon, though refitted for his use since he'll have a human form. And Naruto will also have ghost and dragon attributes, which will be able to apply in combat.
Rules:
Naruto must become Giratina. This is non negotiable.
With oc's, keep them to a minimum. I want as many real characters to attain pokemon abilities, and I don't care if you have to pull in a few characters from Pokemon, regardless of which generation to become a legendary.
With harem, these are a must. Fem haku, fem Kyuubi, and mew (who has a human form)
sakura will not become mew. Ever. She will never become worthy of a legendary, so don't bother. (and on that note, people will only be able to become legendary pokemon, so no regular ones.)
other than that, just do whatever. And let me know if your interested so I can help out more.