Kogu (Hell Demention)

During Dragon Ball Final Attack Goku went to the Hell Demention to fight Hydro Freiza and Mecha Brolybuu. When he realized he could not fight them to his full strength he asked the ghost of picklo to transport him to the alternate demention. He track down him ownself and fused with him ownself to fight Hydromecha Freizabrolybuu (the had fuzed while he was in the alternate demention) but something whent horrible wrong with the fusion resulting in a dark half and light half. he was able to control darkness and lightness and used his final attack the Dark Light Kamayamaya to finally destroy Hydromecha Freizabrolybuu and return the darkside dragonballs to the hell temention.