The Archive of Esoteric Secrets

Sigil of Agony

4-level Conjuration

You conjure a 15-foot-radius sigil on the ground, centred on a space within range. When a creature stands on the sigil for the first time, or starts its turn their, it must succeed on a Constitution saving throw or take 5d6 necrotic damage.
At higher levels: When you cast this spell using a 5th level slot or higher, the damage increases by 1d6, and the radius of the sigil increases by 5 feet for every spell slot level expended above 4th.