One use only. When an enemy cast a spell, the bearer may immediately counter its effects by reading the Sigil of Asuryan to release the spell written upon it instead of attempting to dispel the spell by using dispel dice. This gives them 6 free dice to attempt to dispel the spell, which cannot be combined with any other dispel dice. In addition, the spell is destroyed and the enemy caster loses access to the spell for the rest of the game (note that this has no effect on Innate Bound spells).