Tide of Darkness

You unleash a wave of swirling shadows that fills an area next to you. Each creature in a 10-foot @variantrule[Cube [Area of Effect]|XPHB|Cube] of @variantrule[Darkness|XPHB] originating from you when you cast the spell makes a Wisdom saving throw. On a failed save, a creature takes 2d8 (avg 9) type=psychic damage and is Blinded until it is no longer in the area of @variantrule[Darkness|XPHB]. On a successful save, it takes half as much damage and isn't Blinded. The @variantrule[Darkness|XPHB] lasts until the end of your next turn.

Using a Higher-Level Spell Slot. The size of the @variantrule[Cube [Area of Effect]|XPHB|Cube] increases by 5 feet for each spell slot level above 1.