Crimson Ascension

By offering your own blood and binding it to the dying essence around you, you ascend into a blood-infused trance. Upon casting, you must sacrifice 5 hit points. For the duration:

You emit a 10-foot aura of dripping red mist
Creatures (hostile or not) that die within this aura cause you to regain 5 HP, or if you're at max HP, you gain 10 temporary hit-points.
Once per round when you deal necrotic damage, you may add your proficiency bonus to the damage
If you drop to 0 HP while this spell is active, the blood around you hardens, causing any creature within 5 feet to take 2d6 piercing damage as it shatters and the spell ends.