Goku is the main hero of all of Dragon Ball but here in my online fan-fiction Dragon Ball: The New Hero's. His new apprentice Galrick is the main hero instead. He found Galrick floating in a barren wasteland where Planet Marainia use to be. He sensed great potential took Galrick in and raised him and taught him the ways of a hero and martial arts. He taught Galrick all of his techniques. Including Kamehameha, Instant Transmission, Kaio-ken and Super Dragon Fist. If you want to see info on the real canon version of this character go here Goku.
Its unknown what happened to Goku after that strange cloud of darkness attacked Galrick and Goku. It still remains a mystery.