Alchemical Sludge

You fire a spew of vile ichor in a 5ft wide, 20ft long line. The line originates from a point you can see within 80ft. Any creature caught within the spew must make a dexterity saving throw. On a failure they take 2d8 acid damage and are poisoned. On a success they take half as much damage and are not poisoned. The spew creates a wall of noxious fumes where the line was fired. Any creature entering within 5ft of the wall's area or starting their turn inside it must make a constitution saving throw. On a failure, they inhale the horrible fumes, gaining a level of exhaustion. Any creature immune to poison or that doesn't need to breathe is immune to the noxious fumes. The wall of fumes immediately dissipates when the spell ends.

Using a Higher-Level Spell Slot. The damage increases by 1d8 for each spell slot level above 2.