The Shimada in this fanfic are probably a group with a specific identity. Maybe they are from a particular region in the fictional world. Their dragon - controlling ability might make them both feared and respected. Other characters in the fanfic might interact with the Shimada in different ways, either seeking their help because of their connection to dragons or being in conflict with them out of jealousy or a desire to control the dragons themselves.
One common theme is self - discovery. Shimada often has to figure out his place in the Naruto universe, his powers, and his relationships. Another theme is friendship, like how Shimada forms bonds with other characters in the Naruto world.
In fanfic, it might signify a special bloodline or power exclusive to the Shimada family. It could be a way to create a sense of mystery and uniqueness around the Shimada clan. Maybe it's a plot device to set them apart from other characters and give them a distinct role in the story, like being the only ones with the ability to interact with or command dragons.
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.