Key Stone

Key Stones are used along with a Pokémon with a Mega Stone to Mega Evolve. They are typically embedded in a personal accessory.

Known trainers with a Key Stone

 * Calem/Serena's Mega Ring (as the player)
 * Brendan/May's Mega Bracelet (as the player)
 * Wally's Mega Pendant (uses on Gallade)
 * Korrina's Mega Glove (in Tower of Mastery (games)/around in Kalos (anime only), uses on Lucario)
 * Lisia (uses on Altaria)
 * Lysandre's Mega Ring (in Team Flare HQ in his final battle, uses his specially invented cybernetic "Mega Ring" on Gyarados)
 * Maxie's Mega Glasses (uses on Camerupt)
 * Archie's Mega Anchor (uses on Sharpedo)
 * Diantha's Mega Charm (in Pokémon League (games)/around in Kalos (anime only), uses on Gardevoir)
 * Steven Stone's Mega Stickpin (uses on Charizard and Metagross to become Mega Charizard X and Mega Metagross)
 * Calem/Serena's Mega Ring (as the rival - post-game only, uses on Absol)
 * Red (uses on Charizard to become Mega Charizard X)*
 * Meyer (around in Kalos, uses on Blaziken)*
 * Alain's Mega Ring (around in Kalos, uses on Charizard to become Mega Charizard X)*
 * Remo's Mega Parasol (uses on Garchoo)*
 * Astrid's Mega Earring (uses on Absol)*
 * Siebold's Mega Buckle (uses on Blastoise)*
 * Gurkinn's (around in Kalos, uses on [[Gurkinn's Lucario|Lucario)*
 * Mabel's Mega Staff (uses on Mawile)*

* - Anime only