Essence Leech

You make a small cut in your hand or arm and allow a small amount of blood to flow out, it forms into a bead in your hand that you send out to a creature who has been recently wounded, coaxing more of its blood to spill. Your blood returns to you reinvigorated by the fresh blood of the target creature. To cast this spell you must spend one of your own Hit Die. The target creature must make a Constitution saving throw, roll your Hit Die. On a failed save the creature takes that much damage and you heal for the same amount. On a successful save the creature takes half damage, and you heal for half.