Cage of the Branded One

A number of immobile, invisible, cube-shaped prisons composed of magical force spring into existence around up to 5 areas you choose within range. The prison can be a cage or a solid box, as you choose.

A prison in the shape of a cage can be up to 40 feet on a side and is made from 1/2-inch diameter bars spaced 1/4 inch apart.

A prison in the shape of a box can be up to 30 feet on a side, creating a solid barrier that prevents any matter from passing through it and blocking any spells cast into or out from the area.

When you cast the spell, any creature that is completely inside the cage's area is trapped. Creatures only partially within the area, are automatically thrown into the cage unless they succeed a Charisma saving check with a DC of 15. Upon success, they are thrown away from the center of the area until they are completely outside the area.

A creature outside the cage has no way of entering the cage or damaging the cage. Any attack made against the outside of the cage, causes the creature outside the cage to take 2d6 force damage and is knocked back 10ft. 

A creature inside the cage can't leave it by magical or nonmagical means. If the creature tries to use teleportation, dimension door, or any other move spell to leave the cage, it takes 3d6 fire damage. The creature has a 50% chance to be burned. Flip a coin, if heads the creature is burned and takes a continuous 1d4 fire damage every round. Only the caster can lift the spell. The cage also extends into the Ethereal Plane, blocking ethereal travel.

This spell can't be dispelled by dispel magic.