Blood Prison

You reach out and stop the flow of blood inside of a creature. Choose a target you can see within range that has blood. The target must succeed on a Constitution saving throw or be paralyzed for the duration. At the beginning of each of its turns, the target takes 1d8 force damage, and at the end of each of its turns, it can make another Constitution saving throw. On a success, the spell ends on the target.

Using a Higher-Level Spell Slot. The damage increases by 1d8 and you can target one additional creature for each spell slot level above 3.