A Key Stone is a stone that acts as a medium between a Pokémon Trainer and a Pokémon holding a Mega Stone in order to make them Mega Evolve. A Key Stone is typically embedded in a personal accessory. When the Key Stone is activated, the Pokémon's corresponding Mega Stone reacts to it, starting the process.
Key Stone accessories
A Key Stone can be inserted in various objects so that it can be kept on the owner's person. Many characters use different objects to hold their Key Stones.
Player character accessories
The player character and Damian hold their Key Stones in a Mega Ring, a large black bracelet that is worn on their wrist.
The possession of one Mega Ring is given to the player and Damian by Reukra, who claims it will return information about its usage back to him.
Non-player character accessories
Many non-player characters use different items to carry their Key Stones than the player character.
- Mega Ring