>>58407182Ignore the faggots here and heed this: nobody caught Mewtwo in the mainline games outside of RR and that's from an AU where Protags doesn't exist. Hell, capturing Mewtwo is completely optional, along with completing the Pokédex. It's probably canon that none of the Legendary Pokémon were captured outside of the team you find them with in Masters.
Basically, Mewtwo is in Kalos as a way for the trainers to obtain their Megastones and nothing more. Don't think about it.