As an action, you can create this vial. As an action, a creature can throw the vial at a point within 5 meters, shattering it on impact. Each creature in a sphere centered on that point must make a Fortitude saving throw.
On a failure, it takes 3d8 cold damage and is slowed 1 until the end of its next turn.
On a critical failure, it takes twice as much damage and is slowed 2 until the end of its next turn.
On a success, it takes half as much damage.
On a critical success, it takes no damage.
Augment
You can augment this concoction with the following options, expending catalysts for each option.
You can increase the damage by 1d8 for each additional catalyst expended.
You can expend 1 additional catalyst to increase the slowed level by 1.