Mewtwo

SPECIAL ATTACKER 

(Suitable for Mewtwo Y)

Mewtwo @ Mewtwonite Y
Ability: Unnerve
EVs: 6 Def / 252 SpA / 252 Spe
Timid Nature
- Ice Beam
- Focus Blast
- Fire Blast
- Psystrike

Let's Go, Pikachu! & Eevee!
Mewtwo
Timid Nature
- Psychic
- Recover
- Flamethrower
- Calm Mind

PHYSICAL ATTACKER

(Suitable for Mewtwo X)

Mewtwo @ Mewtwonite X
Ability: Pressure
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Zen Headbutt
- Taunt
- Low Kick
- Stone Edge

Let's Go, Pikachu! & Eevee!
Mewtwo
Jolly Nature
- Rock Slide
- Earthquake
- Brick Break
- Psychic

If you want a build other than what is shown here, you can choose the listing Any Custom Pokemon.