concentration, 1 minute/mana
As an action, corrosive acid eats away at a creature that you can touch or see within 10 meters. At the start of each of its turns for the duration, the creature must make a Fortitude saving throw.
On a failure, it takes 4d6 acid damage and its armor or natural armor is corroded 1 until the end of its next turn.
On a critical failure, it takes twice as much damage and its armor or natural armor is corroded 2 until the end of its next turn.
On a success, it takes half as much damage and and the effect ends.
On a critical success, it takes no damage and the effect ends.
Augment
You can increase the damage by 4d6 for each additional mana expended.