Dragon Ball Kai Episode 13 English Subbed Episode Title:The Power of the Kaio-Ken! Goku vs. Vegeta!.Episode Description:With Vegeta ready to enter the fight, Nappa realizes that he has lost, and decides to attack Gohan and Krillin instead. However, Goku disables Nappa by using his new Kaio-ken technique. With his partner now useless, Vegeta launches Nappa into the sky and mercilessly kills him with a powerful ki blast. Goku tells Gohan and Krillin to leave so he can fight Vegeta without distraction. After moving to a new battleground, the two remaining Saiyans begin their epic battle. However, Vegeta is much more powerful than Nappa was, and Goku eventually realizes that even the two-times Kaio-ken isn't enough to defeat his opponent. He then decides to break his promise to King Kai and risk his own life to use the three-times Kaio-ken.