As an action, you can create this stone. As an action, a creature can throw this stone at a point within 5 meters, where it shatters on impact. Each creature in a sphere centered on that point must make a Fortitude saving throw.
On a failed save, a creature takes 4d6 concussion damage and is deafened for the duration.
On a successful save, it takes half as much damage and isn’t deafened.
A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
You can increase the damage by 2d6 for each additional catalyst expended.