Vampiric Exsanguination [two-actions] Spell 6

You draw in the blood and life force of other creatures through your outstretched arms. You deal 12d6 void damage to living creatures in the area with a basic Fortitude save.
You gain temporary Hit Points equal to half the damage a single creature takes from this spell; calculate these temporary Hit Points using the creature that took the most damage. You lose any remaining temporary Hit Points after 1 minute.