Blackmantle

You weave a mantle of darkness which spreads from your open hand to a point you choose within range. Each creature in a 15-foot-radius sphere centered on that point must make a Constitution saving throw or take 2d10 necrotic damage and any form of healing on them fail for the duration. On a success, they take half damage and suffer none of the additional effects.

At Higher Levels: When you cast this spell using a spell slot of 6th level or higher, the damage increases by 1d10 per slot level above 5th.