It has something along the lines of rendering the target's defense useless per "strike". Meaning it is an extreme case of armour piercing, even when it comes to magic defense.  It does not grant the wielder that power, it would be the weapon's alone.  It can be taken from that weapon and used again but that weapon would become destroyed in the process.  The armour piercing is why the Elven kings held it so dear as it was the "garnish" to a bow that had been passed down through generations, but when they kingdom was to become corrupt and began the slow fall to its own demise a Scholar destroyed the bow to to keep that kind of tool out of the rival's hands.  Then passed the stone to the Guardians to safe keep.