Transfer Life

You touch a living creature that has 0 hit point. The creature gains recovers with 1 hit point. This spell has no effect on undead or constructs. The caster will immediately take 1d4 damage that cannot be reduced, or mitigated in any way. The caster most succeed a constitution saving throw of a DC of 10. A failure will result in the caster suffering 1 point of exhaustion from the sudden loss of life energy.