Beerus would probably win. He has the status of a God of Destruction, which means he has a certain level of power and abilities that are unique. His Hakai ability can erase things from existence. Broly is strong, no doubt, but he is still a mortal (in a sense). Beerus has been shown to be far above most mortals in terms of combat ability and raw power. In a fanfic, unless the writer completely changes the power dynamics, Beerus has the edge.
Well, it really depends on how the fanfic is written. Broly is incredibly powerful with his insane strength and rage - fueled power. But Cell is also no slouch, being a bio - engineered super - being with a wide range of abilities. If the fanfic focuses on brute strength, Broly might have the upper hand. But if it's about strategy and adaptability, Cell could come out on top.
It's hard to say for sure. In the official lore, Broly is extremely powerful with his Legendary Super Saiyan form. But Kale also has her Berserker form which gives her a great boost in power. In a fanfic, it could really go either way depending on how the writer wants to portray their powers and the circumstances of the fight.
In many fanfics, Broly would likely win. Broly is known for his extreme power and near - uncontrollable rage which gives him a huge strength boost. Frieza, while powerful, has been shown to be outmatched by the likes of Goku and Vegeta. And Broly is often depicted as even more powerful than them in some fan interpretations. So, in a one - on - one fight in a fanfic, Broly has a good chance of coming out on top.
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.
Goku could be a likely ally. Despite their initial conflicts, Goku has a way of seeing the good in people. He might approach Broly and convince him that they can work together to win the Tournament of Power for their universe. Their combined strength would be a formidable force.
In a crossover with One Piece, Luffy could be an ally. Luffy is known for his open - mindedness and ability to befriend almost anyone. He would see Broly's power and might try to get him to join his crew or at least fight alongside him against common enemies. They could have some really fun interactions, like Luffy trying to make Broly laugh or share his love for food with him.