The Magic Crystal is a enchanted gem.
This large blue gem is used since time immemorials to protect the magical country known as the Land of Illusion from evil magics. At some point before 1993, it was stolen by the shade of the Horned King, who corrupted its power to return to a physical form, and, now that the Land of Illusion was no longer protected by its spell, rained down curses onto the country. In 1993 however, Mickey Mouse, more-or-less-accidentally sent to the Land of Illusion, managed to defeat the Horned King and retrieve the Crystal, which he gave back to its rightful caretaker, the Good Princess.
Behind the scenesEdit
This Magic Cyrstal was the macguffin of the 1993 video game Land of Illusion.