By raising your hand whilst grasping a rusted chain link, you can open a portal to Carceri. The portal is limited, only allowing hands or chains to grab those who tread on the portal. You create a 15 ft squared surface appearing as a black void, it can be placed on any surface, the floor, a wall, the ceiling, etc. and anything lower than 5 ft above it will be grasped, and move as though on difficult terrain, and they must make a Strength Saving Throw against your spell save DC, becoming grappled on a failed save. When a creature ends it's turn in the area, they must make a Constitution Saving Throw, taking 3d8 piercing damage on a failed save. If a creature is grappled when the spell ends they take 5d10 force damage and are no longer grappled.

The area affected increases by 15 feet for every spell slot level above fourth, and the piercing damage increases by 1d8 for every spell slot level above fourth.