Black Thorn Curse

You place a curse upon a creature of your choice, causing a thorny vine to sprout from their body and ensnare them in darkness.

Choose a creature you can see within range. The target must make a Constitution saving throw. On a failed save, the target is afflicted by the curse and takes 4d8 necrotic damage at the start of each of its turns. The curse also causes the target to be restrained by the thorny vine, reducing its speed to 0 and giving it disadvantage on attack rolls and saving throws.

The target can make a Constitution saving throw at the end of each of its turns to try to break the curse. On a successful save, the curse ends and the vine withers away.

While you maintain concentration on the spell, you can use your action on subsequent turns to cause the thorny vine to constrict, dealing an additional 3d6 necrotic damage to the target. The target can make a Strength saving throw to avoid the additional damage.

At Higher Levels: When you cast this spell using a spell slot of 5th level or higher, the initial damage increases by 1d8 for each slot level above 4th. The additional constriction damage increases by 1d6 for each slot level above 4th.