A brave and heroic warrior, Goku first trained under his grandfather Gohan, who taught him Karate and how to use the staff. He then took his training to the next level under the guidance of Master Roshi, who taught him about energy projection by using the Kamehamea technique. After dying during the fight against his brother Raditz, Goku's spirit underwent training with King Kai, which made him light years more powerful than he had previously been, with techniques such as the Spirit Bomb and the Kao-Ken attack, both of which he had to use against Vegeta.