>>18407901>Reshiram, Zekrom and KyuremThese guys go back to Ho-Oh and Lugia powerlevel tiers. Zekrom is a strong dragon that can create thunderstorms and shit, Reshiram can probably generate enough heat to burn the oxygen in the atmosphere, Kyurem can maybe drop the temperature to almost absolute zero, but all those are power that don't enter the reality manipulation realm. I can see Mewtwo losing against them in the regular forme. Mega = victory
>Yveltal, Xerneas, ZygardeDespite being the Life and Death Pokémon, Xernead and Yveltal are not actually gods that can give life or death. Xerneas is basically a super OP pokémon that creates life energy. I mean it can probably bring someone from the dead by imbuing a corpse with enough life energy but it's not like it's Jesus. Yveltal is a leech on steroids that can suck everyone's Life energy, the side effect being dying. So once again we're dealing with powerful powers, that however don't break the reality. Xerneas probably loses, Yveltal may have a shot depending on how fast it could potentially absorb Mewtwo's energy but I guess it would still fall, Zygarde's powers are unknown so far, but going by the powers of the rest of the trio, I guess it doesn't win either. Mewtwo wins
And well, here's my two cents I guess