Blood summoning

This blood summoning spell uses its power to call upon the blood good to aid the user in battle. By giving the blood God an offering of your own life force, she will send down her power to aid you in the the form of a homunculus made entirely out of blood. This Being is an exact copy of yourself, besides it health, which is your sacrificed health. This being cannot use spells and will last for 5 rounds. If the being is still standing at the end of this time period, it will rush the closest enemy and detonate itself dealing 5d8 necrotic damage in a 15ft cube. Any creature within this 15ft radius must make a dexterity saving throw or risk taking half the damage.