Broly's sad tale is a complex one. He was a Saiyan with incredible potential, but his own people rejected him. The Saiyans were afraid of his power and banished him to a dangerous planet. Growing up in isolation, he developed a violent and angry nature. His only connection to his past was his hatred for Goku, which was kind of misdirected. This hatred drove him to constantly seek revenge, but really it was all because he was so alone and mistreated as a child. He was a victim of his own people's fear and jealousy.
One common theme could be loneliness. Both Broly and Goku have had their moments of isolation. Goku was alone on Earth as a baby, and Broly has often been an outcast. In a sad fanfic, this loneliness could be emphasized, and they might find some sort of connection through their shared feelings of being alone. Another theme could be powerlessness. Despite their great strength, there could be situations where they feel they can't protect what matters to them, leading to sadness.
A fanfic about Broly and Goku being sad could involve many things. Maybe it's about a great battle they had that led to destruction and regret. For example, they might have fought so fiercely that innocent lives were lost, and now they are both sad about the consequences. Or perhaps it could be about a rift in their relationship. Maybe Broly feels misunderstood by Goku, or Goku is disappointed in Broly for some reason.
The main elements include his Saiyan heritage, which gives him his natural strength. His father's role in trying to protect him yet also fueling his anger. And the fact that he was ostracized from his own people due to his power. This isolation and the perceived wrongs from Goku all play into his origin story.
The key elements include his high power level at birth. This led to his exile by King Vegeta. Another element is his father, Paragus, who was with him during his exile. Also, the sense of betrayal and revenge that developed in Broly due to his exile is a major part of his back story.
Another strong opponent could be Hit. Hit has the ability to manipulate time with his time - skip technique. This would give him an edge against Broly. Broly's brute strength might not be enough when Hit can literally disappear and reappear at will, striking at Broly's weak points during his time - skips.
Issei could be one of Broly's potential friends. Issei is known for his friendly and outgoing nature. He might be intrigued by Broly's power and want to befriend him. Also, Asia could be a friend. She has a kind heart and might reach out to Broly, who could be seen as an outcast due to his strength and different background. Her kindness could break through to Broly.
Since Broly is a character from the Dragon Ball franchise, if there is a 'Broly Love Story', it might involve him finding love among the various races in the Dragon Ball universe. Maybe he meets a female Saiyan or someone from another planet and they form a connection through shared experiences, like fighting together against a common enemy. But again, this is all speculation as it's not a common part of the official story.
Broly is a Saiyan. He was born with an extremely high power level. His origin is tied to the Saiyan race. He was considered a threat even as a baby due to his abnormal power. His father, Paragus, was also involved in his story. Broly was exiled because of his power, which led to his vengeful attitude towards Goku later on.
Broly was born on Planet Vegeta. He was an extremely powerful Saiyan. As a baby, his power level was already off the charts which made the king of Saiyans, King Vegeta, fear his potential. So, he sent Broly to a desolate planet to get rid of him. There, Broly survived and grew up in a harsh environment, which further fueled his rage and power.
Since Broly has a rather wild and untamed personality, Naruto could learn to be more in touch with his primal instincts. This doesn't mean Naruto would become a brute, but rather he could find a new balance between his kind - hearted nature and a more aggressive side when necessary. For example, in negotiations or battles, Naruto could be more intimidating. Also, Broly's loyalty to his own beliefs (even if they are sometimes extreme) could inspire Naruto to be more firm in his own ninja way.