uncommon evocation magus sonic 

Cast [>] verbal; Requirements You're wielding a melee weapon in two hands.

You swing your massive weapon, creating a wave of sonic vibrations that topples creatures. Make a melee Strike with your two-handed weapon. Each creature in a 15-foot cone from you must attempt a basic Fortitude save against your spell DC or take 2 sonic damage. On a critical failure, the creature is knocked prone. The target of your Strike must be within the cone or the effect fails.

Heightened (+1) The damage increases by 1.

Secrets of Magic, page 144.