Divine Negation

A dark, misty cloud fills a 20-foot square on ground that you can see within range. For the duration, this mist makes the area lightly obscured.

When a creature enters the affected area for the first time on a turn or starts its turn there, the creature must succeed on a Dexterity saving throw or take 3d6 necrotic damage. While in the mist, creatures cannot cast spells or use features which rely on a connection to a deity, eg a Cleric's Channel Divinity or a Divine Soul Sorcerer's Divine Magic. Any spells or features which deal radiant damage or heal are negated.