In story-line, Illyana was missing for only seconds. But while in Limbo, she experienced the events of several years of her life. She was a small child at the beginning of the story but returned as a teenager. What had happened was the evil sorcerer Belasco pulled her into his dimension in an attempt to make her his dark apprentice. Fortunately for Illyana, that dimension’s version of Storm (who is an elderly sorceress in this reality) and Kitty Pryde attempt to keep her safe from Belasco. The villain’s plan is to use her teleportation powers so he can leave limbo and conquer the Marvel Universe.
And as much as Storm and Kitty want to save Illyana from Belasco, it is up to the young girl to save herself. There is an extra element of difficulty, as if Belasco dies, his soul will wind up possessing Illyana’s body.
Magik is a lot of fun. The story is filled with swords and sorcery, and it makes it pretty different from a lot of the Marvel comics at the time. It’s kind of like the X-Men are hanging out in the He-Man or Thundercats universes. While this isn’t “required reading”, it’s worth reading.
It was written by Chris Claremont, who pretty much did most everything involving any X-Men related character during that time. The art is fine; it’s by John Buscema and Ron Frenz, but what makes it sticks out is all the detailing that inker Tom Palmer put into it. There are all kinds of Easter eggs hidden in the pages that don’t affect the plot, but add nice touches.