The Saiyans arrive. Nappa easily defeats the Earth’s mightiest warriors, killing Chiaotzu, Tien, Yamcha, and Piccolo (who dies protecting Gohan). Goku arrives, fresh from King Kai’s training. He defeats Nappa with ease. Then comes Vegeta — arrogant, ruthless, and powerful. The battle is brutal. Goku uses Kaioken times four to overpower Vegeta’s , but Vegeta transforms into a Great Ape after Gohan’s tail grows back. Crushed, Goku passes the fight to his friends. With Krillin’s desperate strategy and Yajirobe’s surprise sword slash, they cut Vegeta’s tail. Gohan, in a rage, crushes Vegeta’s armor as a Great Ape himself. Vegeta barely escapes on his pod. Krillin spares him on Goku’s wish — a mercy that will later define the universe.
Goku returns to Earth three years later, just in time for a new threat. A rogue supercomputer from Dr. Gero’s lab (created by the Red Ribbon Army Goku destroyed as a child) has unleashed and Android 18 — unstoppable cyborgs. But an even greater horror arrives: Cell , a bio-android from a future timeline. dragon ball z kai complete
Dragon Ball Z Kai: The Complete Saga