As an action, you have resistance to acid damage for the duration.
You can target one additional willing creature that you can touch or see within 18 meters for each additional mana or psi expended. The creatures must be within 9 meters of each other when you target them.
Immunity. You can expend 2 additional mana or psi so you are immune to acid damage.
As a reaction, which you take when you take acid damage, you gain resistance to acid damage until the start of your next turn.
You can expend 1 additional mana or psi to trigger the spell when a creature that you can touch or see within 18 meters takes acid damage. The creature gains the resistance instead.