Mewtwo

Mega Mewtwo Y excels at breaking through defensive and offensive Pokemon alike thanks to its amazing mixed attacking stats and near-unmatched Speed stat. Other offensive Pokemon like Mega Mewtwo X and Mega Gengar are outsped and OHKOed or severely damaged by its attacks, while defensive Pokemon like Zygarde-C, Primal Kyogre, and Celesteela can also be broken through or even OHKOed by some Mega Mewtwo Y sets. Mega Mewtwo Y also has decent bulk and is good at tanking even strong neutral hits, like Boomburst from Pixilate Mega Diancie and Z-Thousand Waves from Zygarde-C, and weaker special hits like Giratina's Core Enforcer do minor damage. That being said, Mega Mewtwo Y struggles due to its offensively poor Psychic typing, which is resisted by several common Pokemon in the metagame, such as Yveltal, Registeel, and Necrozma-DM. This forces it to rely on coverage moves to threaten teams, meaning that Mega Mewtwo Y will often not be hitting as hard as its stats may suggest compared to Pokemon with better STAB types like Mega Gengar, Kartana, and Mega Garchomp. Mega Mewtwo Y's Psychic typing and reliance on coverage moves can also turn Imposter users into an annoyingly bulky hurdle for it, especially considering its good special bulk. Mega Mewtwo Y can be chipped very easily, considering its weaknesses to common moves like U-turn, Spectral Thief, and Knock Off. Lastly, its physical bulk leaves something to be desired, succumbing to priority users like Mega Diance, naturally faster threats like Mega Beedrill, and bulky attackers like Regigigas.

With an incredible stat spread, a fantastic STAB combination, and a good Speed tier, Mega Mewtwo X finds itself as one of the most threatening offensive Pokemon in Balanced Hackmons. Due to its Fighting STAB and high Attack stat, Mega Mewtwo X can pressure Normal-, Steel-, and Dark-types, while its Psychic-type STAB makes Mega Mewtwo X an effective user of Photon Geyser, a powerful move that allows it to get past would-be checks such as Sturdy Shedinja and Fur Coat or Unaware Pokemon. These two types complement each other well, as Pokemon that resist Psychic often don't resist Fighting and vice versa, limiting viable answers to its STAB combination to Pokemon such as Mega Slowbro, Mega Sableye, and Cresselia. Also, with a good Special Attack stat, it can bypass Pokemon that wall physical attackers, such as Fur Coat Pokemon, Zygarde-C and Mega Slowbro, and with its decent bulk it can take neutral STAB attacks in a pinch. For instance, it has the bulk to take Kyurem-B's Extreme Speed, Regigigas's Facade, and Dialga's Core Enforcer. Finally, its high Speed stat in conjunction with its typing allows it to force out or eliminate many Pokemon, including Kartana, Regigigas, Arceus, and Registeel. However, Mega Mewtwo X is still limited by its weaknesses to Flying- and Fairy-type attacks, making it vulnerable to being revenge killed by Mega Diancie, which is very common. Also, it Speed ties with Mega Gengar and is outsped by Mega Mewtwo Y, giving it quite a list of offensive checks. Meanwhile, defensively, though Mega Mewtwo X has few checks in general, Pokemon that do check it such as Mega Sableye, Giratina, and Cresselia consistently do so, as they either resist or are immune to its STAB moves. Also, Mega Mewtwo X can often be OHKOed by slower offensive threats that it cannot OHKO, such as Primal Groudon.