A really interesting plot could be that Broly trains Gohan in a parallel dimension where the rules of power are different. Gohan has to learn to adapt to this new environment while also dealing with Broly's tough training. This could lead to some really cool power - up moments for Gohan.
Well, the plot might involve Broly somehow getting stranded on Earth where Gohan lives. Gohan, being the kind - hearted Saiyan - human hybrid, decides to help Broly adapt. In the process, they train together. Gohan tries to teach Broly about control, while Broly shows Gohan new levels of power. Their friendship grows and they end up protecting Earth from other threats that come their way.
The fanfic might show that Broly, despite his usually aggressive nature, has a soft spot for Gohan's potential. He could see Gohan as a worthy successor to the Saiyan power. So, he trains Gohan with a kind of rough love. During the training, Gohan might struggle at first with Broly's intense regime. But as time passes, he starts to adapt and even surprises Broly with his growth. They could form an unlikely bond through this training process, which could be a central theme of the fanfic.
In a Broly x Gohan fanfiction, Gohan could develop a new understanding of power. Instead of just relying on his academic knowledge and some of his traditional training, he could learn from Broly that power can also be about pure instinct. Meanwhile, Broly could develop his mental faculties. Gohan might introduce Broly to things like meditation or mental focus exercises. As a result, Broly becomes less of a mindless brute when it comes to fighting and more of a thinking fighter, which would be a significant character development for him.
One reason could be the contrast between the characters. Broly is extremely powerful and somewhat of a wild card, while Gohan has his own unique power and personality. Their interactions in a fan - made story can be really interesting.
There may be some out there, but I would not recommend seeking 'lemon' fanfiction as it goes against the family - friendly nature of the Dragon Ball series. Instead, you could look for fanfictions that delve into their relationship in a positive and clean way. For example, stories that show how Gohan's Saiyan heritage affects their relationship or how Videl adapts to being part of the Z - fighter family. There are many creative and engaging stories waiting to be discovered on fanfic platforms.
There are so many fanfics out there, and to find good 'broly x gohan fanfic', you could also join some Dragon Ball - related forums. Fans often share and discuss their favorite fan - made stories there. Maybe someone has already found some great 'broly x gohan' ones and can point you in the right direction.
I don't encourage looking for 'lemon' fanfiction as it often includes inappropriate material. It's better to focus on regular fanfiction sources like FanFiction.net or Archive of Our Own for appropriate Gohan and Videl stories.
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.