Vetio is a Saiyan raised on Planet Vegeta, as a kid he always wanted to become the most powerful Saiyan, he started his training with Gotek, one of his mentors who later fled to Earth. Vetio was a hot headed boy who did't care about his life, only his power but he changed after losing a fight with a other boy due to the fact that he was close to death his power level went up as soon as he healed. Then after he healed his hair changed color and he got a S on his forehead. He became much more powerful and King Vegeta saw his power level was 175,000, making him the strongest Saiyan on planet Vegeta. He then flew to the headquarters of planet Vegeta and said I will be king of this planet. That was the first effect, he was ruthless. He then flew out of the building and shot a energy wave at the building. It fell as soon as it hit, then out of anger he took King Vegeta and said 3 words that were never said, he flew away and never came back to Planet Vegeta. He then went to Earth and became a citizen, most people knew about him because he would destroy buildings. He looks alot like Supea Goku as a Super Saiyan 3.
Vetio's power was a mystery, when he was beat up while he was a boy his power level was 175,000, and after training on Earth for 5 years his power level was 15,000,000. His power was like Broly's power which would grow by just becoming angry. He does show great amounts of power when the opportunity comes.