Just defeat an opponent using Carl exclusive Overdrive Distortion Drive. choose anyone with a second controller, drop his live to the minimum (do the same with Carl, so his Overdrive gauge last longer), activate Overdrive with A+B+C+D and hold D to control Nirvana, then perform the following command while holding it: →↘↓↙←→ D, Nirvana will strike forward and blast them in an energy ball (Similar to Relius Distortion Drive with Ignis)