>>17196216pick what you want to do with him, special attack with mewtwo y, or physical with x, or a mix. if mix, a neutral nature is not so bad
according to those stats, that one has 3 perfect ivs, Hp, spa and speed, then 17 attack and special defense, and 24 defense.
Not bad, But with that stat spread, a Modest/timid nature would be better, you can influence the nature if you bring a pokemon with the synchronize ability and the nature you want the wild pokemon to have, and put it first in your party.
I also think legendary pokemon have 3 guaranteeded perfect ivs on random stats, so you can reset and aim for somehing you like
