As two actions, concussive kinetic energy explodes at a point within 20 meters. The explosion spreads around corners. Each creature in a sphere centered on that point must make a Fortitude saving throw.
On a failure, it takes 7d6 concussion damage and is pushed 3 meters away from the center of the sphere if it is Large or smaller.
On a critical failure, it takes twice as much damage and is pushed 6 meters away from the center of the sphere if it is Large or smaller.
On a success, it takes half as much damage.
On a critical success, it takes no damage.
You can increase the damage by 2d6, push each creature an additional meter, and affect a creature of a larger size for each additional mana expended.