N'Astirh is a fictional demon from Marvel comics who became an enemy of X-Men, X-Factor and Excalibur - amongst other superhero teams and individuals in the Marvel universe. N'Astirh was one of a number of major demons in Limbo, a demonic world originally ruled by the magician Belasco. Like the other major demon-sorcerers, N'Astirh coveted control of Limbo, and desired to become master of Earth as well. He waited and he watched.