Broly is the Legendary Super Saiyan, a warrior born over a thousand years ago with an unusually high power level even at birth. King Vegeta saw him as a threat and ordered his execution, but Broly's father Paragus begged for his son's life. King Vegeta killed Paragus instead. Both father and son were left to die, though Paragus barely survived the blast and Broly not only endured it but grew even stronger. Conveniently, Frieza destroyed Planet Vegeta that same day out of his own fear of the Super Saiyan legend. In the chaos, Broly shielded both himself and his father with a barrier of energy and escaped.
The real problem wasn't Broly's strength—it was his instability. Paragus, terrified of what his son might do uncontrolled, had scientists create a device to suppress him. It worked for a while, and Paragus used Broly as a tool for revenge against Vegeta's bloodline. But when Broly finally faced Goku, the control device couldn't hold him for long. Once he broke free, he became a force of nature, demolishing Goku, Vegeta, Gohan, Trunks, and Piccolo with ease. The Z-fighters had to pool their energy into Goku for one final attack that apparently killed him.
Broly survived. He stumbled into a space pod and crashed on Earth, creating a crater that eventually froze over as he fell into a coma. Years passed—Gohan grew up, Goten was born, and Goku stayed dead. When the younger fighters came looking for Dragon Balls near that frozen mountain, Broly woke up. He tore through Goten, Trunks, Videl, and Gohan until Goku's spirit intervened from the afterlife, helping them send Broly straight into the sun.
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