Keep Stone Weapon (High-Grade)

As a material with defensive properties, keep stone isn't particularly prized for weapons, but it does offer a particular niche. When used with abilities that allow you to use a Strike to counteract spells or magical effects, such as the Sunder Spell feat, the counteract check gains a +2 circumstance bonus. If the counteract check is tied to the Strike's result, add the bonus when calculating your counteract result, but not to the attack roll. Keep stone is treated as adamantine for the purpose of overcoming resistances.