As two actions, a glowing 30-centimeter diameter ball of emerald acid flashes from your hand to a point within 20 meters and then blossoms into an explosion of acid. Each creature in a sphere centered on that point must make a Reflex saving throw.
On a failed save, a creature takes 4d8 acid damage immediately and additional acid damage equal to half the amount of acid damage dealt at the end of its next turn.
On a successful save, a creature takes half the initial damage and no damage at the end of its next turn.
The acid spreads around corners.
You can increase the damage by 1d8 for each additional mana or psi expended.
Delay Blast. You can expend 1 additional mana or psi so the ball lingers at the point of origin while you concentrate on the spell for up to 1 minute. If at the end of your turn the ball has not yet detonated, You can increase the damage by 1d4. When the spell ends, either because your concentration is broken or because you decide to end it, the ball explodes.