Bloodborne Aneuryn

Crimson Rite.  As a bonus action, you can activate any rite you know on a weapon you’re holding. A weapon can only hold one active rite at a time. When activated, you take 1d6 necrotic damage which can't be reduced in any way.

While your rite is active, attacks made with this weapon are magical, dealing an additional 1d6 damage of the type determined by the chosen rite. The rite’s effect lasts until you finish a short/long rest and other creatures cannot gain the benefit of your rite.