How's this?
Shielded by Justice (Su): A throne's innate powers of justice are so strong that some of its wounds are transferred to its attacker. The throne takes only half damage from all wounds and attacks (including that dealt by special abilities) that deal hit point damage. The amount of damage not taken by the throne is taken by the attacker. Forms of harm that do not involve hit points, such as charm effects, temporary ability damage, level draining, and death effects, are not affected. If the throne suffers a reduction of hit points from a lowered Constitution score, the reduction is not split with its attacker because it is not hit point damage.