N'astirh was a demon who helped Madelyne Pryor get her baby back from Mr. Sinister, and then fought the X-Men.
During Limbo's incursion into New York, he decided to send a demon to possess the body of Hobgoblin, thus creating Demogoblin.
He was supposedly killed by a lightning bolt from Storm.
However a demon called N'astirh later appeared later alongside Magik and it is assumed that it is the same demon.
During Hope's return to the present, N'astirh and S'ym cut a deal with Bastion's forces and provided them with a "weaponized ritual" that sent Magik back to Limbo. When the X-Men sent a team to rescue her, S'ym and N'astirh approached Pixie to make another deal: if Pixie would kill Magik, and take her Soulsword to N'astirh, he would return the missing piece of Pixie's soul and free her from Limbo's darkness forever.
