Slayer's Blessing

You carry scraps of materials dangerous to undead and can apply them to your weapon. When you use Slayer's Strike, before making the Strike, you can choose either the Ghost Touch property rune or a precious material: cold iron, darkwood, or silver. Any Strike that gets extra vitality damage from this use of Slayer's Strike also gets the benefits of the rune or counts as that material.

At 14th level, add adamantine and mithral to the list of materials you can choose from.