Dark Ball

The Dark Ball is a unique Pokéball which first appeared in Celebi: Voice of the Forest. It is known to augment a Pokémon's abilities, allowing them to surpass the limits of the original Pokémon's powers. The Dark Ball is also able to bring under control Pokémon that already belong to a Trainer, as well as rendering it utterly void of its free will. However, it is also noted that a particularly strong-willed Pokémon can break free from the control of a Dark Ball, but the repercussions can be equally life threatening for the Pokémon. Pokemon under the influence of Dark Balls also bear similarities to Shadow Pokémon; in both instances the Pokémon are described as "lifeless".