Writhing Agony

You point at a creature within range, and its muscles and nerves become entangled with magic, twisting in painful knots. The target must make a Constitution saving throw. On a failure, the creature takes 2d8 necrotic damage and is wracked with intense, localized pain, forcing it to fall prone and causing its movement speed to be reduced to 0 until the start of its next turn.

While the spell lasts, the target must repeat the saving throw at the end of each of its turns. On a failure, the creature takes an additional 1d8 necrotic damage. On a success, the spell ends.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the initial damage increases by 1d8 for each slot level above 2nd.