Wren's Breath of Belladonna

You consume the belladonna berries used as a material component, taking 1d10 poison damage, and breathe out a poisonous cloud. Each creature in a 15-foot cube originating from you must make a Constitution saving throw. On a failed save, a creature takes 3d10 poison damage and is poisoned until the end of your next turn. On a success, the creature takes half as much damage and isn’t poisoned. A creature that doesn’t need to breathe automatically succeeds on its saving throw.

At Higher Levels. If you use a spell slot of 3rd level or higher to cast this spell, the damage you deal increases by 1d10 for each slot level above 2nd. The damage you take doesn’t increase.

Credit: Created by the World's Beyond Number team for their homebrew Witch class, as seen on "The Wizard the Witch and the Wild One".