Blood Extraction

You conjure a pulsating orb of red energy at a point you can see within range. It lasts for the duration and sheds dim light for 20ft. At the end of each of your turns, until the spell ends, each creature of your choice other than you within 20ft of the orb must make a Constitution saving throw. On a failure, a creature takes 3d6 necrotic damage, or 3d12 necrotic damage if its current hit points are less than or equal to half its hit point maximum. On a success, a creature takes half as much damage.

If a creature is reduced to 0 hit points by this spell, the orb collects some of its blood. It cannot collect blood from the same creature twice. When the spell ends, the accumulated blood strengthens you, granting you 1d6 temporary hit points for each creature the orb collected blood from.

Creatures without blood are immune to this spell.

At Higher Levels: When you cast this spell using a spell slot of 4th level or higher, the damage dealt increases by 1d6 and 1d12 respectively for each slot level above the 3rd.