Master Hand is one of the overseers of the Nintendo Megaverse, accompanied at all times by his “brother”, Crazy Hand. He is responsible for protecting order in the universes under his watch, and has often covertly aided heroes and champions in these universes. Although his work often opposes that of his brother, the two never directly fight, each aware of the necessity of the others actions.
Master Hand has worked behind the scenes for countless years, but has never directly interfered with mortal beings. That changed when the Omniversal Council, a governing force of the Omniverse's higher entities, demanded Master Hand and Crazy Hand assemble a task-force to oppose Dr. Doom, the dictator of Latveria from Realm-616, and his attempts to break Omniversal law by conquering other universes. The task-force, called the Super Smash Bros. was formed from the greatest heroes and villains of the Nintendo Megaverse, with the mission of defeating Doom and restoring cosmic balance.
As a cosmic entity, Master Hand is capable of near-godlike acts, including (but not limited to) creation of inter-dimensional portals, firing lasers or explosive, bullet-like projectiles out of his fingers, and propulsion through the air with rocket-like force. Although he possesses major durability, and is a true immortal, his form can be temporarily destroyed if it sustains enough damage. In addition, he can be killed if the Nintendo Megaverse is destroyed.
"Welcome, heroes, to your greatest test."
"We must waste no time."
"Doom is a threat to us all."
"Cast aside your differences."
"Leave order wherever you tread."
"You have your commands."
"The spread of evil must be curbed."
"This is truly our greatest challenge."