Acrid Chorus

You select a point within 90 feet of you to harness vitriolic energies and open several small portals to an alternate plane, from which screaming and howling can be heard and propelling forth terrible acid. While you are concentrating on this spell, an area within a 15x15 foot Cube will have creatures of your choice take 4d6 Acid damage at the start or end of their turn if they are still within this area. For every instance of Acid damage they take from any source while within this area, they lose -1 AC, -5 feet of movement speed, and have a -1 to all attack rolls, ability checks, and saving throws as a combination of sizzling acid and distracting screams interferes with their focus; this effect stacks up to 5 times. They also have Disadvantage on Concentration saving throws and Wisdom (Perception) checks made based on hearing. Deafened creatures do not have Disadvantage on Concentration saving throws or or the -1 debuff.

Using a Higher-Level Spell Slot. The damage this spell does increases by 1d6 for each spell slot level above 5. At 9th level, the radius and the negative effects of this spell are doubled and chosen creatures cannot maintain Concentration within the area.