Blood Strike

You cut yourself on the weapon used to cast this spell, dealing 1d6 slashing damage to yourself which cannot be reduced or negated. Afterwards, your weapon is empowered by your life blood, causing it to deal an additional 2d6 damage on its next hit before the spell ends (damage is the same as the normal damage dealt by the weapon). You cannot cast Blood Strike on a weapon that is already under its effect, but you can cast it on several different weapons in quick succession. 

Cantrip Upgrade. The self damage dealt by this spell and the bonus damage it applies to the weapon it is used on are increased to 1d8/2d8 at 5th level 1d10/2d10 at 11th level, and 1d12/2d12 at 17th level.