Shao Kahn is the emperor of Outworld in the main Mortal Kombat storyline.
Shao Kahn first appeared as the final boss of Mortal Kombat II. He is portrayed as a powerful warlord who has conquered numerous realms and seeks to expand Outworld’s dominance through invasion, political manipulation, and tournament victories.
His title and role distinguish him from Shang Tsung, who is generally depicted as a sorcerer and servant or agent of greater rulers. Onaga, meanwhile, is the former Dragon King and a separate major antagonist introduced in Mortal Kombat: Deception.
Shao Kahn’s recognizable design includes a skull-like mask, a large war hammer, and imposing armor. Although his exact position changes across alternate timelines and story arcs, “emperor of Outworld” is his defining canonical title.