Accel World: Infinite Burst

A mysterious black cloud kicks Haruyuki and his friends out of the online fighting game Brain Burst. Unable to reenter, they discover that this isn't just an isolated incident-the cloud is spreading and preventing other Burst Linkers from accelerating. Haruyuki and the others soon learn that, to protect the bond that connects them, they must confront a powerful ancient being that been sealed away since the dawn of the Accelerated World!