Ultra Shield

You must be holding a shield to use this spell. You draw upon almost all of your strength to cast a giant force field that radiates 80 ft in all directions away from you. When you cast this spell, the power you expand causes you to lose health points equal to a 4d8. Enemies may pass through it and attack once they are inside the radius. Any attack made towards you or anyone else protected by this shield is nullified if the attacker is outside of the spell's radius.