As two actions, you direct wave after wave of concussive kinetic energy in a sphere centered on a point within 20 meters. The sphere spreads around corners and remains for the duration. A creature that enters the spell’s area for the first time on a turn or starts its turn there must make a Fortitude saving throw.
On a failure, it takes 2d8 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.
As an action, you can cause the onslaught to move 2 meters in a direction that you choose at the start of each of your turns.
You can affect a creature of a larger size and push each creature an additional meter for each additional mana expended and increase the damage by 1d8 for every two additional mana expended.