Blood Blade

You bite your finger and create a blade from your blood. At the time of casting you take 1d4 force damage. This damage cannot be reduced in any way. You forge a shortsword of blood which you are proficient with. You use your casting stat for attacks made with this weapon. It deals 1d6 magical slashing damage. When you kill an enemy with this blade you gain temporary hit points equal to the number of hit die that creature possessed. If you kill multiple enemies you may add new temporary hit points together with temporary hit points previously gained with this spell instead of the normal temporary hit point rules. These hit points go away when this spell ends.

At higher levels: When you reach character level 5, the weapon counts as a +1 weapon. At character level 11 the damage dealt increases is changed from 1d6 to 1d10 but the self damage increases to 2d4 force damage. at character level 16 the weapon counts as a +2 weapon.