Your genes are modified with Mew DNA. You gain powers similar to a Mew, including a Psychic typing, the ability to learn any move, and even to transform into various Pokémon forms, changing your stats, typing, and gaining new abilities corresponding to your new form. You could become a Legendary comparable to the likes of the Creation Trio with time and effort, but for now, you're essentially just Level 1, only able to hit a little harder and transform into a Mew form enhancing your physical abilities as well as allowing you to levitate.