By having them interact with different characters in the fanfic world. If they meet someone who has different values or beliefs, it can cause them to re - evaluate their own and grow as characters. Also, giving them personal goals and showing how they strive to achieve them can add depth to their development. For instance, if one wants to be more confident in public speaking and the other wants to learn a new skill, and they support each other in these pursuits.
They can be developed through facing challenges. For example, if they encounter a difficult puzzle or enemy, they have to use their wits and skills. This shows their growth.
One idea could be a time - travel plot where they end up in a different era and have to adapt together. Another could be a mystery - solving adventure where they team up to figure out a strange occurrence in their fictional world.
Pacman could be developed by showing his vulnerability. Usually seen as a strong and fast dot - eater, in the fanfic, he could be in situations where he's not so confident. For example, when facing a new kind of threat in Pinky's world. Pinky, on the other hand, could be developed by showing her kindness. We usually see her as a chaser, but here she could be shown as a protector, protecting Pacman from other threats in the game world.
For Rex, you could develop his character by showing his more vulnerable side when he's around Breach. Maybe he's usually the tough leader, but with Breach, he allows himself to show his doubts and fears. For Breach, show how he matures through his interactions with Rex. For example, he could become more responsible.
For Snivy, you can show its growth from being a bit naive to more confident. For example, at the start, it might be hesitant in battles, but as the story progresses, it becomes bolder. Servine can be developed as a more mysterious character at first, with its past gradually being revealed as it gets closer to Snivy.
For Error, you could develop his character by showing his softer side when he's around Ink. Maybe he starts to care more about the things Ink creates instead of just wanting to destroy them. As for Ink, he could become more understanding of Error's glitches and not just see him as a nuisance. The lemon could be a factor in this development. For example, if the lemon has some sort of calming effect on Error, Ink could use that to his advantage to get closer to Error.
For Rukia, her character could be developed by showing her learning new skills or techniques from Sode no Shirayuki. This would not only make her stronger physically but also show her growth in terms of her adaptability. For Sode no Shirayuki, we could see her develop more of an emotional side as she spends time with Rukia. Maybe she starts to understand human emotions better.
To develop Divine, you could start by exploring their backstory. Maybe they come from a long line of magic - users but have a unique power that sets them apart. This could lead to internal struggles as they try to master this power. For Legeater, perhaps focus on their physical abilities and how they got them. Were they trained by a master? Or did they develop them through self - discipline?
To develop the characters in a 'naegi x harem fanfic', consider their backstories. If one of the female characters had a difficult past, it can shape how she approaches Naegi and the other harem members. Also, let their relationships with Naegi evolve over time. Maybe at first they're just friends, but as they face challenges together, their feelings change. You can also use dialogue to show their growth. For example, a character who was initially quiet starts to speak up more as she becomes more confident in her relationship with Naegi.
For Blue, start by giving them a distinct personality. If they're a cricket fan, show what makes their love for the sport unique. For example, do they have a favorite old - time player? As for the other characters, like the cricket players in the fanfic, show their on - field and off - field personalities. Maybe one player is really tough on the field but a softie off it.
For Johnny, you can start by giving him a strong motivation. If he's a vampire hunter, it could be revenge for a family member killed by vampires. As he meets Dracula, his views start to change. For Dracula, explore his long life experiences. Maybe he's tired of the eternal darkness and sees something different in Johnny.