Mega Man 10 centers on a cure for what robot virus?

Mega Man 10 centers on a cure for the robot virus Roboenza.

Roboenza suddenly spreads among robots, causing malfunctions and rebellion. Mega Man’s sister Roll becomes infected, while eight Robot Masters go rogue and threaten the world. Dr. Wily claims to possess a machine capable of producing a cure, prompting Mega Man and Proto Man to recover it.

The plot eventually reveals that Wily created Roboenza and developed the cure as leverage. Mega Man himself contracts the virus, but Roll gives him her prototype medicine. After defeating Wily, Mega Man and Proto Man secure enough medicine to help the remaining infected robots.

Roboenza is not the same as the Sigma Virus or Maverick Virus. Those names belong primarily to the Mega Man X continuity, whereas Roboenza is the distinctive infection introduced in this tenth classic-series game.