Blood Maelstrom

As an action, you conjure a devastating vortex of razored blood in a 20-foot-radius cylinder centered on a point you can see within 60 feet. Creatures in the area that have blood must make a Constitution saving throw (DC = 8 + your proficiency bonus + your spellcasting modifier). On a failed save, a creature takes 6d8 necrotic damage or 6d8 slashing damage, is knocked prone, and cannot regain hit points until the end of your next turn. On a successful save, the creature takes half as much damage and suffers no additional effects. Creatures reduced to 0 hit points by this effect have their hearts automatically shredded and absorbed, counting as hearts consumed for your Heart Consumption feature (you choose which hand gains each heart). At Blood Tier 2 in at least one hand, the damage of this feature increases to 8d8 necrotic damage or 8d8 slashing damage, and the area becomes difficult terrain of writhing blood until the start of your next turn. At Blood Tier 3 in both hands, the damage increases to 10d8 necrotic damage or 10d8 slashing damage, the area expands to a 30-foot-radius sphere, affected creatures have disadvantage on their saving throws against this feature, and any creature reduced to 0 hit points by this effect can be instantly converted into a blood-forged weapon or barrier of your choice as part of the same action, gaining the benefits of Blood Bending at its maximum tier for 1 minute.