Well, in some fanfictions, she might be depicted as the devil through her actions. Maybe she's shown as being manipulative, using her charm to get what she wants from others, much like how the devil is often portrayed as a tempter in traditional stories.
In this type of fanfiction, Bella Swan could be seen as the devil in terms of her relationships. For example, she might break hearts or lead people astray in their emotional lives. It could also be that she has some sort of dark power that she uses for her own gain, which is a characteristic often associated with the devil. So, her actions and motives in the fanfiction might be what makes her the devil figure.
In the 'bella swan is the devil fanfiction', her character transformation into the devil could be symbolized by a change in her behavior. She may start to show a lack of empathy, being cruel to those around her. Perhaps she's involved in some sort of power struggle where she uses underhanded tactics, similar to how the devil is known for trickery. This change in her from the original Bella Swan we know could be how the author makes her into the devil in the fanfiction.
Chapter 411, "You Really Hold a Strong Grudge", is the clearest early answer because it turns Hua Country's situation into a concrete plot event. It opens with The lead director, who understood the entire process, had an...
Chapter 233, "Individual, Ten, Hundred, Thousand... Million, Ten Million, Damn!!!", is the clearest early answer because it turns Tianyi's situation into a concrete plot event. The chapter turns that into something concrete by moving from [What the hell, what's this about life span ending??
Chapter 338, "The Adulterer is Far on the Horizon, Yet Close Before the Eyes", is the clearest early answer because it turns Li's situation into a concrete plot event. Early on, Tang Jinyu, dressed in a light apricot Cheongsam, sat indifferently....
Chapter 210, "Are All of Jiang Li's Fans Hidden Big Shots?", is the clearest early answer because it turns Miss Jiang's situation into a concrete plot event.
Chapter 463, "Even if it's a Wild Boar, I'm Willing!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from The evening glow gradually bathed Dragon Ridge Island in a dazzling...
Chapter 587, "Has He Also Become a Part of the Play?", is the clearest early answer because it turns Isn's situation into a concrete plot event.
Chapter 137, "Lai Fu's Death Has Another Cause", is the clearest early answer because the violence around Aunt Ying becomes final instead of hypothetical. Early on, Jiang Li personally went to Lai Fu's tomb and performed a small....
Chapter 306, "I Believe Whatever Miss Jiang Says!", is the clearest early answer because it turns Jiang Says's situation into a concrete plot event.
Chapter 669, "My First Love Sister Who Died Young", is the clearest early answer because it turns Xi Yang's situation into a concrete plot event. The chapter turns that into something concrete by moving from Bang," the door closed, but Chen Qijun's words lingered in Tai Fan's...
Chapter 265, "This Time You Must Help Me", is the clearest early answer because it turns Weibo's situation into a concrete plot event.