Who are X Platform?

Imagine a colorful variety of totally awesome and badass video game characters emerged from your TV screen and upon entering reality decided to form a music band, harnessing the incredible power of a mysterious technological marvel of a device that allows them to transform sweet melodies into magic and utilize these abilities to save the entire world from an indomitable oppressive force that threatens the happiness and well-being of the good people of said world.

... That's X Platform. ;)