Void of Acamar

You invoke the ravenous void of Acamar. A 5-foot-diameter pulsating, black void appears in an unoccupied space of your choice within range and lasts for the duration. Any creature that ends its turn within 5 feet of the void must make a Dexterity saving throw. The creature takes 1d8 force damage on a failed save, or half as much damage on a successful one. On a failed save the creature must roll a d4 if they are of Medium size or less, on a one, the creature takes another 1d8 bludgeoning damage and is transported to a harmless demiplane as they fall into the void. Any object of Medium size or less within 5 feet of the void on the end of your turn or which is thrown into the void is always transported to the demiplane, and is not damaged by the void. The caster cannot enter or be harmed by their own void, but they may allow willing creatures to enter the void without taking damage or failing the saving throw.

As a bonus action at the beginning of your turn, you can move the void up to 30 feet in any direction. If you ram the void into a creature, that creature must make the saving throw against the void's damage, and the void stops moving this turn.

The demiplane created by the void is the same every time the caster uses the spell, and each is unique to the caster. The demiplane appears to be an endless void dimly lit by some unseen light source from above, but is in actuality only stretches 20 feet in each direction. Gravity and air are nonexistent inside the demiplane. No creature inside the demiplane requires air, sleep or food, and all methods of telling time cease working upon entering the demiplane. No creature inside the demiplane can fall unconscious, and if they were upon entry they wake up once inside. Any fire that can be extinguished by water is extinguished upon entry and no fire of this sort can be lit inside the demiplane. Ranged spells cannot enter the demiplane, neither can they be cast inside the demiplane. Any creature that entered willingly or that the caster is currently willing to let exit may exit the demiplane at any time. A creature may stay inside the demiplane as long as they wish, although staying long-term is dangerous as no creature in the void can age and thus they can easily lose track of time. Once the caster is no longer concentration on the instance of this spell that a creature fell into, said creature can exit the void at any time they wish, regardless of whether the caster is willing to let them. Once a creature decides to exit the demiplane, they will reappear into the nearest unoccupied space to where they were when they fell into the demiplane. The caster may retrieve any item inside the demiplane at will as long as they are are within 5 ft. of the void.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, both types of damage that can be inflicted increases by 2d8 for each odd-numbered slot level above 3rd.