Death n decay

A circle of necrotic energy forms in a 60-foot area from a point you choose within range. Each creature in that area must make a Constitution saving throw. A target takes 6d6 necrotic damage on a failed save, or half as much damage on a successful one.The Creature is also at half movement speed until It leaves the area of effect.
If a creature starts or ends it turn within the spells area of effect they will take an additional 3d6 Necrotic damage.

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