Dying of The Light

7th-level evocation (shadow)

Casting Time: 1 action
Range: 120 feet
Components: V, S, M (a black pearl worth 250 gp)
Duration: Concentration, up to 1 minute

A wave of withering darkness erupts from you, filling a 120-foot-radius sphere and extinguishing any nonmagical light sources in the area. Any light produced by spells of 6th level or lower is dispelled. Magic items (but not artifacts) that give off light have that property suppressed while in the spell’s area. Any light sources brought into the area during the spell’s duration are likewise extinguished.

Light-producing spells of 7th level or higher function within the area.

Nonmagical light sources removed from the area can be reignited. Magic items regain their ability to give off light 1 round after leaving the area. This magical darkness foils darkvision, except for creatures that can see in magical darkness, such as devils. You can see within the area of the spell as if it were brightly lit.

Each creature you choose to be affected that ends its turn in the darkness takes 4d8 necrotic damage and gains one level of exhaustion. A successful Constitution saving throw halves the damage and negates the exhaustion.