As an action, a tidal wave surges forth from you or retreats to you. Choose to have the wave surge or retreat. Each creature other than you in a sphere centered on you must make a Reflex saving throw.
On a failure, it takes 1d10 bludgeoning damage, is knocked prone if it is Medium or smaller, and is pushed or pulled 2 meters away from you or toward you (pushed if the waves surged, pulled if the waves retreated) if it is Medium or smaller.
On a critical failure, it takes twice as much damage and is pushed or pulled 4 meters away from you or toward you (pushed if the waves surged, pulled if the waves retreated) if it is Medium 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 1d10 and affect a creature of a larger size for each additional mana expended.
You can expend 2 additional mana so it deals no damage, but the waves surge continuously. The duration changes to 1 minute/mana, concentration and the waves surge toward and away from you in an aura shaped as a sphere. Until the spell ends, the aura moves with you, centered on you.
Whenever a creature enters the area for the first time on a turn or starts its turn there, it must make the Reflex saving throw.
You can change the direction of the waves as an action.