Darkrai Galaxia

Galaxia changes one night when Meta Knight has a nightmare caused by Darkrai. Galaxia somehow gains his powers and turns into Void Galaxia. It now has the power to bring nightmare creatures from the enemy's worst fears. The jewel has been replaced by a dark vortex that has no end and by staring into it the enemy will fall into an everlasting nightmare. Its most powerful move is MetaKnightmare. Meta Knight stabs his foe and enters their dreams and torments them until they become too scared of him to fight anymore.