Explosive Wave (3.5e Invocation)

To do an explosive wave, a Saiyan Warrior creates a 2 layer force field of energy around himself. As a standard action he uses his ki to force the outer field of energy out away from himself causing a wave of force energy to explode in all directions from the Saiyan Warrior out to a range of 15 feet in all directions, bullrushing all creatures within 15 feet of the Saiyan Warrior to the edge of the energy wave, and then explodes with outward force dealing 1d4 damage per 1/2 of the Saiyan's hit dice rounded down (minimum of 1d4). Any creatures struck by this explosive energy are sent flying back an additional 5 feet per 3 points of damage dealt.