For Stefan, Elena's death could be a huge blow. He might go into a deep depression or spiral out of control as he had always been so in love with her. Damon, too, would be severely affected. He might become even more vengeful and angry, blaming himself or others for her death.
Caroline would be heartbroken. She was Elena's best friend. Her death could make Caroline more determined to protect the town from further harm, as a way to honor Elena. Bonnie might also feel a great sense of loss. She had always used her magic to protect Elena, and her death could make Bonnie question her powers and her purpose. In general, the whole Mystic Falls gang would be thrown into chaos, and their relationships with each other would become more strained as they deal with their grief in different ways.
For Bonnie, Elena's death could be a huge blow. Since they are best friends, Bonnie might be consumed by grief and use her magic in dangerous ways, either trying to bring Elena back or lashing out at those she blames. Caroline would also be devastated. She would probably try to keep the group together in the face of this tragedy, but also struggle with her own sadness. And for the other characters in Mystic Falls, Elena's death could change the power dynamics. Some might see it as an opportunity to gain more control, while others would be afraid of the chaos that could follow.
Jeremy's death in fanfiction can have different impacts. His friends in the Salvatore brothers might become more vengeful. They could go on a rampage to find out who was responsible. Elena might struggle with her vampirism even more, as she has now lost her last remaining family member. Some fanfictions might show that Caroline steps up to be more of a support for Elena, filling the void left by Jeremy's death.
For Stefan, if Katherine dies, it could be a huge emotional release. He has been so tangled up with her for so long. Her death might finally let him move on completely and focus more on his relationship with Elena or just find peace on his own.
Caroline would also be devastated. As Stefan's friend, she would have to deal with the loss. It could make her more determined to protect the town from any threats, as a way to honor Stefan. Bonnie might try to use her magic to bring him back, which could put her in a dangerous situation, especially if it involves dark magic. The other vampires in Mystic Falls would also feel the impact. Some might see it as an opportunity to gain more power, while others might fear for their own safety as the power balance in the town shifts.
Often in fanfiction, their character development is intertwined. As they interact more, they both change. Rebekah might become more empathetic due to Elena's influence, and Elena could become more street - smart in the ways of the vampire world with Rebekah's guidance. Their relationship could shift from one of animosity to one of mutual respect and friendship, which is a significant development for both characters in the Vampire Diaries fanfiction universe.
Caroline, for example, might be more accepting as she is also a vampire. She could help Elena adjust to her new life. Damon, on the other hand, might be jealous or feel threatened that Stefan made Elena a vampire. It could change the power balance between the three of them.
Damon's compulsion of Elena can completely change the trajectory of their relationship. It might make their relationship more passionate in some cases. For example, if he compels her to be more honest about her desires, it could lead to a more open and intense connection. However, it can also be a source of mistrust. If Elena discovers that Damon has compelled her without her knowledge, it could seriously damage their relationship and take a long time to repair.
The Originals might also play a role in 'vampire diaries elena bashing fanfiction'. Elijah, for instance, who has his own code of honor, might be written as disapproving of Elena's actions and behavior. Rebekah, with her jealousy towards Elena in the show, could be further explored in fanfictions that bash Elena. Kol could be shown as having no patience for Elena's antics. These characters from the Originals can add more complexity and different perspectives to the fanfictions that are critical of Elena.
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.
One reason for Elena bashing in fanfiction could be that some fans prefer other characters over her. For example, they might be big fans of Bonnie or Caroline and feel that Elena gets too much attention in the show. So in fanfiction, they might downplay or 'bash' Elena to give more focus to their favorite characters.