In some fanfiction, their hatred could be a result of misinformation. Maybe they heard false rumors about each other from their friends. So a plotline could be that they start to uncover the truth behind these rumors. As they do, they begin to question their hatred. Or perhaps they have different beliefs or values, such as Edward believing in a strict code of conduct and Bella being more of a free spirit. Their differences in these areas could lead to clashes and hatred, and the story could be about how they either learn to accept each other or continue to butt heads.
One possible plotline could be that they are forced to work together on a school project despite their hatred. As they interact, they start to discover things about each other that they didn't like before but now see in a new light. Another could be that they are competing for the same thing, like a scholarship or a lead role in a play, and their hatred fuels their competitiveness. A third plotline might be that they are neighbors and keep getting into petty arguments over things like noise or property boundaries, which gradually escalates their mutual dislike.
A plotline could involve Edward being part of a group that Bella doesn't like, and vice versa. For example, Edward could be in a clique that Bella thinks is snobby, and Bella could be in a group that Edward finds too rowdy. Their hatred could be based on these group associations. Also, maybe there was an incident in the past where one of them accidentally wronged the other, like Edward accidentally ruining Bella's art project or Bella spilling something on Edward's important papers. This initial event could be the root of their hatred.
Chapter 257, "Building a Straight Road, the Beast Meat Issue", is the clearest early answer because it turns Mirror Valley's situation into a concrete plot event. A useful checkpoint is the way the scene starts with The dividing line of a day in the Ice Abyss is determined by dawn. and follows through with If they breakthrough to the Earth-digging Realm, they can even....
Chapter 260, "Medicine Workshop Upgrade, Population Surge, and Resource Easing", is the clearest early answer because the rescue effort creates visible on-page results. The setup is From April 29 to May 9, the massive population migration finally..., but the pressure keeps building through By the morning of May 10, when Xia Hong once again checked the system....
Chapter 299, "Troops at the Gates, Searching, Completely at a Loss (2)", is the clearest early answer because it turns Longyou Army's situation into a concrete plot event. The setup is Li Xuanling heard this and immediately frowned., but the pressure keeps building through The harsh environment of the Ice Abyss has already determined that....
Chapter 262, "Garrison Candidates, Martial Arts Enthusiasm, and the Eve of a Breakthrough Tide", is the clearest early answer because Thousand Forged Weapon finally turns buildup into a real advancement. A useful checkpoint is the way the scene starts with The deeper purpose, of course, is for next month's martial arts... and follows through with After thinking for a moment, he took a few things with him and....
Chapter 281, "Yang Li's Repression and Resentment (Part 2)", is the clearest early answer because it turns Beast Blood's situation into a concrete plot event. The chapter gives readers a real answer by opening on Hearing the chill in Yang Zhong's voice, Yang Yue shivered slightly,... and ending on Li Hu's right arm was wrapped with cloth strips, stained with quite a.... In story terms, the chapter closes with Depositing them was such, using them was even more troublesome;
Chapter 284, "Astonishing Training Results, the Peepers", is the clearest early answer because it turns Cold Beasts's situation into a concrete plot event. The chapter turns that into something concrete by moving from Second Year of Great Xia, June 25 Snowy night, west of Wushuang,... to But at this moment, the situation seemed peculiar..
Chapter 312, "Regaining Focus, Killing, Shock, and Submission (Part 3)", is the clearest early answer because the violence around Peng Bo becomes final instead of hypothetical. Early on, Those seem to be the families of Meng Ying, Jiang Ping, and several.... By the end, With a slight wave of Xia Chuan's hand, Yue Feng and the others....
Chapter 205, "The Director Emerges, Treasure Presentation Opportunity (3)", is the clearest early answer because Lin Kai gets a payoff that changes the stakes. A useful checkpoint is the way the scene starts with Leader, this must be the Great Xia Leader..." Xiang Liang looked at... and follows through with This is my only chance, I must seize it." Looking at the wooden box....
Chapter 223, "Outbreak of Battle, Breaking the Siege, Honored Guest", is the clearest early answer because the buildup finally cashes out in a real clash. It opens with As his name suggested, Hou Hu's image was not much different from... and closes on According to what he previously overheard about Hou Tong on the.... The key payoff is that the danger stops being abstract and the conflict around Long Mountain becomes immediate, forcing the surrounding cast to react under pressure.