As two actions, acidic rain falls to the ground at a point within 100 meters. Each creature in a cylinder centered on that point must make a Fortitude saving throw.
On a failure, it takes 3d10 acid damage immediately and additional acid damage equal to half the amount of acid damage dealt at the end of its next turn and its armor or natural armor is corroded 1 until the end of your 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 your next turn.
On a success, it takes half as much damage.
On a critical success, it takes no damage.
You can increase the damage by 1d10 for each additional mana expended.