Items, Mega Stones, #702
Mewtwonite Y flings for 80 power, a Mega Stones item since Generation VI
PokéAPI item 702 of 2,223, Mega Stones category, Items pocket
Effect, in PokéAPI's words
Mewtwonite Y: “Held: Allows Mewtwo to Mega Evolve into Mega Mewtwo Y.”
Games
Mewtwonite Y is listed in the text of 5 version groups, first in Generation VI
Game index by generation
IIIIIIIVVVIVIIVIIIIX
Named in
X and YSun and MoonUltra Sun and Ultra MoonLet's Go Pikachu and Let's Go EeveeSword and Shield