If Goku had killed Vegeta during the Saiyan Saga of Dragon Ball Z, several consequences would have unfolded: 1. Loss of Potential Allies: Vegeta later becomes a strong ally to Goku and the Z Fighters in their battles against future adversaries like Frieza and Cell. Without Vegeta, these confrontations would have been much more challenging, as he played a crucial role in their victories. 2. Weakened Power Levels: Goku's power level would not have received the necessary boosts he achieved by fighting against Vegeta. Training with Vegeta and the subsequent battles allowed Goku to push his limits, unlocking new powers like Super Saiyan, which became crucial in future sagas. 3. Battle against Frieza: Vegeta's knowledge of Frieza's weakness and his rivalry with the tyrant played a significant role in the fight on Planet Namek. Without Vegeta, it would have been harder to defeat Frieza, and even if Goku eventually achieved Super Saiyan, the process could take longer or be less effective. 4. No Majin Vegeta: During the Buu Saga, Vegeta becomes Majin Vegeta, displaying immense power and contributing to the overall storyline. Without this transformation, the events leading up to the final battle against Majin Buu would have been significantly altered and potentially more difficult. However, it is important to remember that Dragon Ball's storyline is vast and complex, meaning that the absence of one character would likely result in alternative storylines and new developments.