Well, as humans, Elena could be less of the damsel in distress. She could be more assertive and have her own set of goals that don't revolve around vampires or the supernatural. For Klaus, he could lose his violent tendencies and instead be a more brooding artist type. He might use his creativity to deal with his past traumas.
In a human version, Elena could be a fearless journalist always on the hunt for a big story. Klaus could be a mysterious and wealthy entrepreneur who is trying to hide some dark secrets from his past. As they cross paths, Elena starts to dig into Klaus's secrets. Their relationship develops as Klaus tries to keep her at bay while also being drawn to her tenacity. This is very different from their original vampire - related characters.
If we make them human, Elena could be a very social and outgoing girl who loves adventure. She could be into extreme sports and traveling. Klaus, on the other hand, could be a shy and introverted writer. They meet in a writing workshop where Elena encourages Klaus to come out of his shell. Their relationship grows as Klaus writes about their experiences together, and they both change in the process. Their development is not related to the vampire - werewolf drama of the original.
Ben could be more outspoken in fanfiction. In the show, he's often a bit reserved as a ghost. But in fanfiction, he could be the one pushing Klaus to face his demons more directly. This would show a different side of Ben, perhaps one that was hidden in the show because of his limited means of communication as a ghost. It also changes the nature of their relationship, making it more of an equal partnership in growth.
Well, in fanfiction, you could develop Sgt Frog's human form character by emphasizing his confusion in the human world more. For instance, he could constantly misinterpret human social cues, leading to humorous situations. Maybe he thinks a simple handshake is a sign of a lifelong bond and gets really attached to people after just one handshake.
Naruto could be given a more complex personality in the modern fanfiction. He might be more introverted at first, having to deal with the loss of his father in a modern way (like through memories in a digital photo album). Kushina, on the other hand, could be shown as having a secret past that is slowly revealed through modern - day detective work by Naruto and his friends, which would be a big departure from her straightforward backstory in the original.
Dark Naruto could be developed to have a different set of ninja skills. He might learn some forbidden jutsu on his own in his journey to the dark side, which gives him an edge over others. In terms of Fem Sasuke, she could be more in tune with her feminine side. Instead of just being cold and brooding like the original Sasuke, she could use her charm and intelligence to get what she wants. For instance, when dealing with enemies, she might use her wits to outsmart them rather than always relying on brute force. Also, Dark Naruto could have a more philosophical side, constantly questioning the nature of power and the ninja world, which is different from the more impulsive original Naruto.
One way their characters are developed differently in fanfiction is through their parenting styles. In the original series, since they die early, we don't really see them as parents. But in fanfiction, we can see different approaches. Minato could be the strict yet loving father, teaching Naruto advanced ninjutsu from a young age. Kushina could be the nurturing mother, always making sure Naruto is emotionally okay. Additionally, their characters can be developed in relation to the political situation of the village. They could be involved in secret political maneuvers to protect the village and Naruto's future as a potential great ninja.
Sasuke in fanfiction could be developed with more vulnerability. In the original series, he is often seen as stoic and brooding. But in fanfiction set in the ANBU world, he might show his fears and doubts more as he has to deal with the high - stakes and secrecy of ANBU missions. Sakura could be more assertive. In the original, she sometimes seems to be in Sasuke's shadow. Here, she could be an equal or even a leader in ANBU operations. The ANBU environment forces both of them to grow in new ways.
In fanfiction, their characters can be developed in various ways. For example, Kallen might be more open about her feelings towards Lelouch earlier than in the original series. Maybe she directly confronts him about her admiration and loyalty, which could lead to different relationship dynamics.
Well, in some fanfictions, Harry's relationship with werewolves could be explored in a much deeper way. He might develop a more empathetic side towards them, especially if he meets a werewolf who is not as bloodthirsty as the ones he has encountered before. Hermione could be developed to be more of a risk - taker. When it comes to werewolves, she might be willing to put herself in more dangerous situations to study them or help them, which is different from her usually cautious self in the original series.
In fanfiction, their characters might be developed with more emotional depth. For instance, Percy could be shown to be more vulnerable about his feelings for Annabeth. Maybe he has nightmares about losing her and this makes him more protective in a different way than in the original. He might be more open about his fears, which wasn't really explored as much in the original.
In the original series, Naruto is mainly focused on becoming Hokage and getting Sasuke back. In the fanfiction, as Anbu Naruto, he might be more secretive and have a darker side. He could be more cynical about the village's politics. Female Sasuke, on the other hand, may be more independent than in the original. She could be more involved in political matters in the village rather than just seeking revenge. For example, she might use her skills to try and reform the ninja system.