Mr. X

Mr. X (ミスターエックス) is a fake identity of Dr. Wily's, which he used to mask his true identity in Mega Man 6. Mr. X is a mysterious billionaire of unknown origin that is the leader of the X Foundation. He sponsors the World Robot Alliance and is the sponsor of the 1st Annual Robot Tournament. In the beginning of Mega Man 6, he takes control of eight of the strongest Robot Masters in the final event of the tournament to help him conquer the world. Before he was revealed to be Dr. Wily in disguise, Mr. X mentioned that he was the one who manipulated Dr. Wily into helping him take over the world.

X Crusher
In Mr. X's Castle, Mr. X fights with an iron ball type machine called X Crusher (Ｘクラッシャー) that swings in the screen and shoots a purple ball that splits in two when it touches the floor, each part sliding a different direction. Mr. X seems to have motion sickness while using it. When the machine is destroyed, he flies out from it and reveals that he is really Dr. Wily before escaping to his Wily Castle.

Strategy
Stay to one side and attack it by using any weapon (Flame Blast is its weakness). Dodge the energy balls by jumping. A good strategy is to use a charge shot. The Rush Power Adaptor also sends the crush flying back if a charged shot is used, and deals 4 damage per hit.

Manga
Mr. X also appears in the Rockman 6 manga in a role similar to that which he played in the games. He again claims to have manipulated Dr. Wily from behind the scenes, and unleashes the Mega Man 6 Robot Masters as seed players in the World Robot Championship Tournament. As in the game, he is discovered to be a disguised Dr. Wily.

Archie Comics
In the Mega Man comic by Archie Comics, a wanted poster for Mr. X appears in Roslyn Krantz and Gilbert D. Stern's police office. He is also mentioned in issue 48, where he was revealed to be responsible for recovering Dr. Wily from the destroyed third castle. Mr. X made his first physical appearance in issue 49. He revealed himself to Dr. Wily as he awoke from his injuries from fighting Mega Man. Mr. X informed Wily that his organization was responsible for recovering his body and supplying him with medical care. As such, Wily was in his employ. He told Wily that he had seen the future and that humanity had embraced robotics. He required Dr. Wily, as he needed to unleash a "monster" onto the world, making people realize their mistakes. He supplied Wily with a new lab and informed him that it was time to build more Robot Masters.

Trivia

 * Just before unmasking himself, Mr. X cries out: "My plan for world domination has faild". This typo was fixed in the Mega Man Anniversary Collection.
 * Mister X is commonly used as a pseudonym for someone whose name is secret or unknown.