The origin of Kate Kane and Jacob Kane varies in different comic interpretations. Kate Kane is known as Batwoman. Her origin often involves her military background and her decision to take on a vigilante role in Gotham. Jacob Kane, her father, is also an important figure in her story. He has his own military and family - related past that intersects with Kate's journey.
Well, if '100 bellamy and kane fanfiction' is what you have, it might mean there are 100 different fan - created stories about Bellamy and Kane. Fanfiction often takes the existing characters and settings from a show like 'The 100' and spins new tales. Bellamy is known for his leadership and Kane for his more traditional leadership style. Fanfictions might explore how they combine their leadership skills, or their interactions with other characters in new and exciting ways. It could also be a code or something specific within a particular fanfiction community, but without further information, it's just speculation.
One key element is Kate's military experience which was cut short and led her to seek a different path in Gotham. For Jacob, it's his position in Gotham's power circles. Another element is their family bond which is tested as Kate becomes Batwoman.