The Carnage Rapier

Weapon Finesse +1 Rapier Rare (this item requires attunement)

No amount of time spent cleaning and maintaining this weapon removes the old, ingrained bloodstains. They are evidence of its power and purpose. When this weapon is used to make an attack, the dweomer within the blade activates. If one of the damage dice used in association with the weapon deals the maximum damage possible, roll an additional die of the same type and add the result to the damage dealt.