In this fanfic, the author could explore the origin of Broly's transformation into a Super Saiyan God. It might be a unique journey, different from how Goku and Vegeta achieved it. Perhaps there's a special training regimen or a hidden power within Broly that was awakened. The story could also delve into how the other characters in the Dragon Ball universe react to Broly's new form. Do they fear him? Admire him? And how does this change the power dynamics in the overall story? There could be epic battles against new foes that only Broly in his Super Saiyan God form can handle.
A unique plot makes a Broly Super Saiyan God fanfic stand out. For example, if it focuses on a previously unexplored aspect of Broly's character in relation to his new form. Maybe it shows his softer side that was hidden before.
If Broly participated in the Tournament of Power, he would be an absolute powerhouse. His raw strength and uncontrollable rage could either make him a wild card that disrupts the whole tournament or a key player for his team. He might start by randomly attacking opponents without much strategy, but as the fight goes on, his natural fighting instincts could kick in and he could become a real threat to the strongest fighters in the multiverse.
Bulma could be another character paired with the reborn Broly. She might be the one to help him understand the modern world if he is reborn in a different time period. She could use her intelligence to create devices that help Broly control his power better or she could just be there to provide some comic relief in the midst of all the intense Saiyan drama.
He could team up with Luffy. Luffy is always open to new allies, and Broly's power would be a great addition to the Straw Hat crew. They could go on adventures together and face powerful enemies.