Demon Surge (魔幻の波動 Magen no hadō, lit. Wave of Illusion) is a monster-only spell from Fire Emblem: The Sacred Stones, and is primarily used by Gorgons. When cast, this spell will engulf the selected enemy target and entrap him/her within a menacing orb of darkness. Forks of nefarious lightning will then cascade down upon the target, transforming the orb into a wicked tornado that swirls around him/her before rupturing.
When obtained through the enemy control glitch, this spell may be used by any unit, regardless of whether they are physical or magic-based. However, only magic-based units will display battle animations when casting the spell. Tethys will also use this spell, but if she attempts to attack twice, while the battle animation is on, the game will freeze.