The official Pokémon movie website has updated. Translations follow:

Announcing the Results of the Mewtwo Strikes Back Evolution Drawing Contest!

This drawing contest was held in collaboration with 12 Shogakukan magazines!
We received lots of entries from Pokémon Fan, Kindergartener Magazine, TV-kun, First Grader Magazine, Pucchigumi, Ciáo,
Corocoro Comic, Shonen Sunday, Corocoro Aniki, Corocoro Ichiban!, Shogakukan Kids,
and Sunday Webry x Pixiv this year as well!
We will now announce the grand prize winners through lucky prize winners from each magazine!!

Click to see the winning artwork:























Source: http://www.pokemon-movie.jp/illust_contest_result/