Blood Weapon

You take 1d6 points of damage that can’t be mitigated. By doing so, you can create a replica of a simple or martial melee weapon made of solid blood; this weapon deals an additional 1d8 necrotic damage. On a critical hit with this weapon, it deals an additional 1d8 necrotic damage (this damage isn’t affected by critical hits); when this occurs, the weapon dissolves and you regain hit points equal to half the necrotic damage dealt by your critical hit.

You can’t cast this spell if you are a construct, undead, or plant.

At Higher Levels. When you cast this spell by spending Mana points equal to a 3rd-level spell or higher, the additional necrotic damage dealt by the weapon increases by 1d8 for each spell level above 2nd.