A Z-Crystal is a special item in the Pokémon video game series that enhances a Pokémon's abilities during battles. Each Z-Crystal corresponds to a specific type of Pokémon, such as Fire or Water, and allows the Pokémon to perform powerful moves called Z-Moves. These moves can only be used once per battle, making them strategic tools for trainers. To use a Z-Crystal, a Pokémon must hold the crystal and the trainer must have a corresponding Z-Ring. When activated, the Z-Crystal unleashes a unique and powerful attack, showcasing the bond between the trainer and their Pokémon. This feature adds depth to battles and encourages players to explore different strategies.