Hemoplague

This spell is only accessible to Scarlet Glyph Arcane who reach 20th level.

You infect a 10-foot radius area at a chosen point within the spell’s range with a virulent plague. Creatures in that area must make a Constitution saving throw. On a failed save, at the end of your next turn they take 12d6 necrotic damage and become vulnerable to necrotic damage for 1 minute. If the creature has resistance or immunity to necrotic damage, that resistance or immunity is ignored for the duration. On a success, the creatures take half damage. In addition, you regain hit points equal to half the amount of necrotic damage dealt by this spell.

A creature affected by this spell must make a Constitution saving throw at the start of each of its turns, pre-ending the spell’s effect on a success.