Black Hole Pulse

An aura of crushing force envelopes you. Each creature within range must make a Dexterity saving throw. A target within 5 feet takes 8d6 force damage on a failed save, or half as much damage on a successful one. The damage is decreased by 2d6 for every 5 feet between you and the target (6d6 at 10 feet, etc). Targets too far away to take damage are unaffected.

The aura spreads through walls.

If you move your arms or legs for any reason, the spell ends.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage at every distance increases by 1d6 for each slot level above 3rd. This can increase the range of the aura.