Ace: Ok Mewtwo vs Shadow got to go with Mewtwo

Jax: Got to agree lets go with why he can teleport see the future read and control minds

Ace: Reflect attacks heal from wounds create barriers confuse his foes and fire energy attacks like swift and shadow ball

Jax: He has so much power he teleported a lake underground along with a group of Pokémon and five humans and didn't show any sign of being tired or drained were as shadow unleashing his full power tires him out very fast and super form doesn't last very long

Ace: Plus it would know all of shadows moves before he makes also physically attacks won't do much since their not very effective also Mewtwo is much smarter he built his own lad and cloned Pokémon their given all their abilities Mewtwo can simple outlast shadow

Jax: And Mewtwo can mega evolve alone which greatly increase power health defense attack sp defense sp attack and speed

Ace: And it can use moves like confusion safe guard disable swift future sight psych up miracle eye psycho cut guard swap power swap recover psychic barrier aura sphere amnesia mist me first psystirke rock smash strength and dive Mewtwo x can use in addition low kick taunt earth quake ice punch and stone edge y can use ice beam focus blast shadow ball electric ball fire blast and clam mind

Jax: So Mewtwo has a higher chance here