Their relationship could develop uniquely if Charlie starts teaching Renesmee about human history and culture. Since she has a vampire side, she might view things from a different perspective, and this exchange of ideas could deepen their bond.
Maybe Renesmee saves Charlie from a dangerous situation in a very unexpected way, like using her vampire - human hybrid abilities in a creative manner. This would make Charlie see her in a whole new light and cause their relationship to grow in a different direction. He might become more protective of her but also more in awe of her powers.
One way is to put them in a situation where they have to rely on non - verbal communication. Maybe they are in a place where sound is not possible. They would have to learn to read each other's expressions and body language more deeply. This would force them to understand each other on a different level and strengthen their relationship. Also, they could be given a shared power that they can only use when they are in complete harmony. This would require them to work on their relationship constantly to be able to access this power.
One unique way to develop their relationship is through music. Charlie loves music and uses it as a form of therapy in the hotel. If Adam has no interest in music at first but Charlie slowly gets him involved, it could be a really interesting way for them to bond. They could write a song together about their experiences in Hell and what they hope for the future. This musical journey could bring them closer together in a very different and special way.
Their relationship could be developed through shared hobbies. For example, if they both like painting, they could have painting sessions together. This would allow them to bond over their creativity and get to know each other better on a friendly level.
Their relationship could be developed in a unique way if Joker starts to see Poison Ivy as more than just an ally in crime. For example, he could start to be genuinely interested in her plants and how they work. This newfound interest could make Poison Ivy see him in a different light, and they could start to bond over creating new plant - based weapons together.
Their relationship could be developed uniquely by having Lila actually start to feel guilty about her lies when she sees how kind Adrien is. She might slowly try to change her ways, and Adrien, being the good - hearted person he is, could help her become a better person. This would be a very different take on their relationship compared to the usual animosity.
Their relationship could develop uniquely if Rachel takes on a teaching role for the younger glee club members under Will's guidance. This role reversal would force them to see each other in new lights and create a deeper bond.
A unique way to develop their relationship could be through a series of challenges. For example, they are trapped in a mysterious dimension together and have to rely on each other to escape. In the process, they discover each other's strengths and weaknesses, and Kurama realizes that Kushina is not just Naruto's mother but a powerful ninja in her own right. This mutual respect and reliance would strengthen their relationship.
Their relationship could be developed uniquely by having them start as enemies in a sense. For example, Sephiroth could be on a mission that Aerith unknowingly gets in the way of. But instead of killing her immediately, he's intrigued by her. This initial encounter could spark a series of events where they keep crossing paths. Each time, they learn a bit more about each other. Maybe Aerith starts to see the pain behind Sephiroth's cold exterior, and Sephiroth begins to respect Aerith's strength and determination. Over time, this could lead to a complex relationship that is part friendship, part something more, as they both struggle with their own destinies and how the other fits into it.
Another way to develop their relationship uniquely is if Aipom gets a prophecy about a great danger that Ash will face in the future. Aipom decides to secretly train itself extra hard to be able to protect Ash. When Ash finally discovers what Aipom has been doing, he is touched and their relationship becomes even stronger. This would show a different side of their relationship, with Aipom being the protector instead of the one usually being protected by Ash.
Their relationship could be developed through a shared love of transfiguration. Hermione could seek out McGonagall for extra lessons and in the process, they bond over the beauty and complexity of the subject.