Eldritch rend

Objects in a 20-foot Cube within range emit a dim purple light (your choice). Each creature in the Cube also emits light and takes 3d8 if it fails a Constitution saving throw. For the duration, objects and affected creatures shed Dim Light in a 5-foot radius and has disadvantage on attack rolls against creatures within 10 feet of it. Affected creatures gain 1 level of exhaustion for 1 round.