Note to everyone:

If your character's weapon is covered in auren, then you will need to recover the weapon in Auren after a fight in order to keep it lethal. It's just a simple maintenance thing, but it could be useful later. 

Edit: Also I've decided to create an alloy containing mostly auren and iron called "Roalin". It's not as effective as solid auren, but it can still cause damage to angels. However, it requires more contact. So either the metal needs to stay inside of the angel, or more cuts need to be made with the metal.