Devour

The difficulty of this spell is equal to twice the difficulty of the spell it is being cast against. When you observe a spell being cast you may cast Devour as an instant action. The spell automatically fails.
 * Spell Difficulty: X
 * Spell Duration: Instant
 * Spell Range: Sight
 * Spell Type: Restricted Lost (Counter)

(Notes: Only the most powerful of ancient mages have ever learned this spell. Those mortals who know it guard its existence carefully. How did you find it?)