Dessicating Breath

You spew a cloud of black dust that draws all
moisture from the air in a 30 ft cone. Creatures
in the cone make a Con save. A creature takes
5d10 poison damage on a failure and is poisoned,
or half as much on a success and isn't poisoned.
At Higher Levels. When you cast this spell using
a spell slot of 5th level or higher, the damage
increases by 1d10 for each slot level beyond 4th.