Goten and Trunks successfully master the complex Fusion Dance inside the Hyperbolic Time Chamber, merging their bodies and spirits into the arrogant but unimaginably powerful warrior, Gotenks. Meanwhile, on Earth's surface, a bizarre friendship forms between Majin Boo and the comedic World Champion, Hercule Satan, briefly causing the monster to renounce his evil ways. However, when ruthless human gunmen shoot Hercule, Boo's intense sorrow and rage causes him to expel his pure evil side, resulting in a dark evolution known as Super Boo. The newly evolved monster immediately teleports to the lookout, invades the Hyperbolic Time Chamber, and engages a fully powered Super Saiyan 3 Gotenks in a chaotic, reality-tearing brawl.