Well, her character could be much darker. In the original show, she has a certain lightness to her despite the supernatural chaos. But in the fanfiction with abuse, she might be full of anger and mistrust. Maybe she starts to push people away more often, not believing they could truly care for her, as she has been so badly hurt.
In such fanfiction, Elena might be portrayed as more vulnerable. She could be shown as constantly on edge, her confidence shattered compared to the somewhat more resilient Elena in the original series. This is because the abuse she endures changes her psyche. For example, she might be more hesitant in her relationships, fearing further harm.
In fanfiction, Elena is typically the damsel in distress type at times, but also with a strong moral compass. She's trying to navigate the chaos of the vampire world while holding onto her humanity. Katherine, on the other hand, is more of a femme fatale. She's not afraid to use her sexuality and cunning to get what she wants. For example, she might manipulate the Salvatore brothers with ease, while Elena is more hesitant and sincere in her relationships with them.
In Vampire Diaries fanfiction, Elena is portrayed as the sweet and loving character. She values her relationships and is very empathetic. For instance, she'll comfort her friends when they are in trouble. Katherine, in contrast, is more of a survivor. She has a long history of manipulating people to stay alive. She might use her charm to deceive others, while Elena would use her charm in a more sincere way to build relationships. This difference in their personalities makes for some interesting storylines in fanfiction.
In some fanfictions, Elena's autistic sister might be portrayed as having unique sensitivities. For example, she could be highly sensitive to sounds or lights, which might play a role in the Vampire Diaries' supernatural setting. Maybe she has a special connection to the vampires or other supernatural beings because of her different way of perceiving the world.
One common theme could be her struggle with PTSD. After the abuse, Elena might constantly relive the trauma, which could be shown through nightmares or flashbacks. Another theme could be her isolation. She may push away her friends, like Stefan and Damon, because she doesn't want them to see her as weak or damaged. Also, there could be a theme of revenge. Elena might seek to get back at her abuser in some way, either through direct confrontation or more devious means.
Elena's character may become more cautious. For example, she might be more hesitant to trust new people. She could also develop a stronger will. After experiencing abuse, she might be determined not to let it break her and instead use it as fuel to become a better fighter. Maybe she starts training harder to protect herself from future harm.
In the show, Mason was killed off rather quickly. In fanfiction, their relationship could develop more fully. For example, Mason could survive and he and Elena could start to date secretly. Their relationship might be a slow - burn, with them getting to know each other's secrets and fears over time.
One common plot device is the use of flashbacks. These flashbacks can show the moments of abuse Elena has endured, adding depth to her current state of mind. Another is the introduction of a protector figure. This could be a new character or an existing one from the Vampire Diaries universe who tries to rescue Elena from her abuser.
A fanfiction could explore the idea that Elijah's desire for Elena is part of a bigger prophecy. Maybe there's a hidden message that says if Elijah and Elena are together, it will bring peace to the vampire and human world. So he's driven by this sense of duty as well as his personal feelings for her. This would lead to a lot of internal conflict for Elijah as he tries to balance his feelings with the potential consequences of their relationship.
It really depends on the perspective. Elena is often seen as the good girl, the one with a pure heart. She represents the moral compass in many fanfictions. But Katherine has this allure of mystery and a long history of survival. If you like characters with depth and a darker side, Katherine might be better in the fanfiction world. However, if you prefer the more traditional heroines, Elena would be the top choice.
In this fanfiction, Elena could start off as a more adventurous character. When she meets Damon, she's not as focused on the normal things in her life like school and friends. Instead, she's eager to explore the unknown with Damon, which would lead to a different kind of relationship. She could be the one dragging Damon into new situations rather than the other way around, and this would shape her character in a unique way.