Riku is the descendant of Goku. He is the father of Goten Jr and husband of Asper. Dubbed as the Dragon of the West, he is a member of the Mighty Dragons. As a founder of the New Z Fighters, he is one of the strongest there are.
Riku has wild, untamed hair much like his ancestors. Like his ancestors, he has slightly tanned skin. His hair is black, unlike his sister's brown hair. He usually wears a red gi over a long sleeve yellow undershirt with red pants and a turquoise sash. After training with Majuub, he was given a red gi with a black long sleeve undershirt with red pants and a turquoise sash. Also black gloves, boots, and a yellow cape. Everything black is weighted. Like all the Saiyans of his generation, he has a brown tail.
Riku is a prankster, often never taking anything seriously. But that changes when he fights, somewhat. Riku is often seen gawking at girls, even during battles as seen when the New Z Fighters fought Oceanus Shenron, telling her she was hot.
At a young age, Riku was pushed into training. During this training, his anger boiled over and caused him to transform into a Super Saiyan.
Super Saiyan 2
Between the time of the battle Ultimate Cell and Rigor, Riku somehow accessed the power of Super Saiyan 2. He looks a lot like Gohan in this form.
Super Saiyan 3
During his training, Riku accessed the power of Super Saiyan 3. He is able to sustain the form.
Super Saiyan 4
After the battle with the Shadow Dragons, Riku learned how to transform into the Super Saiyan 4 form.