Bloodflame Soulsiphon

Each creature in a 60-foot cone must make a Dexterity saving throw. A creature takes 5d6 fire and 5d6 necrotic damage on a failed save, or half as much damage on a successful one. creatures dropped to 0 hit point by the flame die, and the caster heals 4d6 hit points for each creature killed this way

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the damage increases by 1d6 of each type for each slot level above 5th.