You inhale a large breath, then pull fiendish acids into your
lungs, then exhale a brown acidic cloud in a 15’ cone. Creatures
in this cone make a Constitution save or take 2d8 acid damage
and acid begins to corrode their weapons. A nonmagical weapon
has a -1 penalty to attack and damage rolls permanently. A
magical weapon has a -1 penalty to attack and damage rolls for
the duration, or until a creature uses their action to clean the acid
off the weapon.

At Higher Levels. When you cast this spell using a spell slot
of 3rd level or higher, the damage increases by 1d8 acid damage
for each slot level above 2nd.