Dissidia Duellum Final Fantasy

A giant crystal appears in the city of Tokyo. The blue-glowing crystal blended into daily life and became a familiar presence. However, those peaceful times came to a sudden end. Strange monsters appear from a mysterious, menacing energy polluting the crystal, driving humanity to despair. As terror dominates the city, armed warriors emerge, as if they were answering to a cry for help. As they conceal their identities and quickly disappear after battle, people began to call them 'ghosts'...