Crismon Curse

By Draining your own blood, reducing you to a critical state, strengthen your blood magic. This is obviously a last ditch effort.

For every ten points of your own hit points you sacrifice, when you make a spell or melee attack that hits. You roll a extra 1d6 necrotic damage to that attack. This ignores resistances, makes immunities into resistances and deals x4 damage to creatures weak to necrotic damage.