"It's a scroll that can invoke the Halo of Vengeance spell. Powerful. Tomas or Kelgar should have the skill to tap into it, or I could of course. Only one use, though. Hm, this place does some strange things to magic. We should hurry up and get out of here..."
Halo of Vengeance: Surrounds the target with a magical shield that absorbs all effects from 1D6 attacks per turn. The effect persists indefinitely until a 1 is rolled or until the target moves.