Only one race begins the game with an Illusion spell an Altmer Dragonborn, with the rage-inducing spell Fury. Some beings are entirely immune to Illusion magic. The effectiveness of Illusion spells depends on the caster's skill and the foe's resistance to the spells or spells in general. Casting Illusion spells consumes Magicka. Casting Illusion spells raise the corresponding skill. Targeted Illusion spells include Calm, Frenzy, Fear, or Courage and spells cast on one's self such as Muffle or Invisibility. Illusion is one of the six skills that fall under The Mage play-style. 'You're the one that casts those illusions.