Anya's Symphonic Cube

You perform a brief but moving musical phrase whose ethereal notes and staves form translucent golden faces of sonic force that arrange themselves into an immovable cube around an area you choose within range. Once formed, the interior of the cube fills with compelling sounds that grow to an overwhelming symphonic performance. The cube can take the shape of a cage of up to 20 feet on each side with 1/2 inch diameter bars spaced 1/2 inch apart; or the shape of a box up to 10 feet on each side comprising a solid barrier that prevents any matter or cast spells into or out of the cube's area.

Creatures only partially within the area of the cube, or those too large to fit inside the area, when the spell is cast are pushed away until they are completely outside the area and takes 2d12 thunder damage and 2d12 psychic damage. Any creature within the cube while it is intact is resistant to thunder damage, resistant to psychic damage, resistant to cold damage, cannot hear anything outside the cube's area, and automatically fails perception checks that rely on hearing.

If any creature comes into contact with a face of the cube, the face erupts with flame, and the creature takes 4d8 fire damage.

A creature cannot enter or leave the cube by nonmagical means. If any creature attempts to enter or leave the cube's area by magical means, such as a teleportation spell (Misty Step, Far Step, or similar) and including travel through the Ethereal Plane, it must first make a Charisma saving throw. On a failure, the creature takes 3d12 thunder damage, takes 3d12 psychic damage, wastes the use of the spell or effect used to make the attempt to enter or leave the cube, and is Stunned until the end of their next turn. On a success, the creature takes half of this damage, is not Stunned, and successfully leaves or enters the cube.

You may use an action to destroy the cube. When you do so, its faces explode with a loud, dissonant chord, whose notes begin to careen wildly. Each creature that was inside the cube's area or within 15 feet of its edges when it is destroyed in this way must make a Constitution saving throw and Wisdom saving throw. On a CON failure, the creature takes 5d12 thunder damage and is Stunned until the end of their next turn. On a success, a creature takes half of this damage and is not Stunned. Each creature that fails this save by 5 or more is Deafened for 1d10+1 hours. On a WIS failure, the creature takes 5d12 psychic damage, or half as much on a success. If a creature fails this save by 5 or more, they must roll a d100 on the Indefinite Madness table. If a creature fails both saves by 5 or more in this way, it is Incapacitated for 1 minute.

You may also use an action to simply dismiss the cube and end the spell early.

This spell can't be dispelled by dispel magic.