It really depends on the writer's intention. Sometimes Bella wins if the story is about her growth and empowerment. For instance, if the fight is about her independence, she might stand her ground and make Edward see her point of view.
It really varies. In some fanfictions, Harry wins because of his natural talent and the power of love and friendship that he has on his side. He has his Gryffindor courage which gives him an edge in the fight.
Well, it could be about Harry Potter getting into a battle to gain custody of something or someone. Maybe it's about him fighting for the custody of a magical creature or even a young wizard in need of protection. He might use his magic skills and the support of his friends to win the custody battle in this fan - made story.
Obviously, Harry Potter is a main character as the title implies he is the one fighting for custody. There might also be his friends like Hermione and Ron who could be helping him out in the battle for custody. Maybe the person or thing he is fighting for custody of could also be considered a main character in a sense, as it's the central object of the story.
Shaggy would probably win. Shaggy has shown to have some really out - of - this - world abilities in some of his own storylines. He could use his unpredictability to catch Yamcha off guard.
For Yamcha, you can focus on his growth from being a bit of a comical character to a more serious and respected fighter in the context of his relationship with Frieza. Maybe he learns from Frieza's cold and calculating nature how to better strategize in battles. For Frieza, his development could be about him learning to care for someone other than himself. He could start to see Yamcha as an equal, which is a huge shift from his usual superiority complex.
The story is set in a world of advanced military technology and follows the adventures of the main characters as they face various challenges and enemies. There's a lot of action and strategic planning involved.
You can also make him have a unique role in the story. For instance, he could be the one to discover a new threat to the Earth before anyone else. He then has to convince the other Z - Fighters to take this threat seriously. This would put him in a leadership position and make him stand out more.