He is a Pre-teen whos 12, and meets Goku and the Z-fighters when he lands on Earth with his best friend Mumba. Kuzons is Gokus biggest fan, and even left his planet to visit him. Just before Planet Vegeta blew up, 2 saiyans, a male and female were heading towards a random planet due to pressing a button in a hurry to get off Planet Vegeta. The saiyans land on a planet with a unknown race. The saiyans plan to destroy the planet for Frieza, but are relaxed by the races delights. 7 years later, the Saiyans had a child, Kuzon. Kuzon grew up and trained with his father and made a friend out of a member of the race, Mumba. Mumba grew up with Kuzon and trained with him. When Kuzon was 7, Kuzon was asleep, At the same time, Broly had finnaly been defeated and a spirt Somehow, flowed from Brolys inner body, all the way across the galaxy, to the planet where Kuzon was with his parents. The spirt flowed in his body and made Kuzon the next, Legendary super saiyan.
4 years later, Mumba became a spaceship engineer and Kuzon heard of Goku and that he was a hero. So Kuzon wanted to visit Earth to meet him, so Mumba built a spaceship for him and Kuzon. Mumba and Kuzon flew to Earth and within a year they made it to Earth and Kuzon met Goku and read Kuzon the 3rd legendary super saiyan to find out the rest!