In another scenario, Batman takes Catwoman to their favorite rooftop in Gotham where they often meet. He has set up a beautiful, simple dinner with candles. After a heartfelt conversation about their journey together, from being enemies to lovers, he pulls out a ring with a diamond that has a unique shape, perhaps resembling the bat - symbol, and asks her to marry him.
She might be very surprised at first. After all, Batman is not one to show his emotions so openly. But then she would likely be overjoyed. She has deep feelings for Batman too, and this proposal would be a confirmation of their complex relationship.
One of my favorite scenarios in Batman saves Catwoman fanfiction is when it takes place during a city - wide disaster. Batman has to fight through chaos to find Catwoman, who might be trapped in a collapsing building. It shows his determination to save her no matter what.
A scenario could be that Batman gets injured badly during a fight. Catwoman has to take care of him and in the process, she sees a more vulnerable side of him. This makes her realize that he's not just a symbol, but a man. Batman, on the other hand, sees her kindness and realizes that she has more depth than he initially thought. This changes their dynamic, with Batman being more open to her ideas and Catwoman being more committed to helping him in his mission.
One interesting scenario could be that Arthur plans an elaborate proposal in a secret, enchanted garden. He decorates it with magical lights and rare flowers. Another could be that he proposes during a grand feast, in front of all their friends and allies, making it a very public and joyous occasion. Or perhaps he takes Merlin on a quest, and at the end of it, when they've achieved something great together, he pops the question.
In a fanfiction, Naruto might plan a big public proposal. He could gather all their friends and family in the Hidden Leaf Village. He would make a big speech about how Hinata was the one who saw him when others didn't, and her love changed him. Then, with everyone watching, he would pop the question.
One scenario in the fanfiction could be that Batman gets jealous when he sees Catwoman flirting with a rich businessman during one of her heists. He might start to question her motives and their relationship. This jealousy could cause him to act out of character, perhaps being more aggressive or possessive towards Catwoman than he normally would be. And Catwoman, being the independent character she is, would not take kindly to this sudden change in Batman's behavior, leading to a rift between them that would be interesting to explore in the story.
One idea could be that Batman and Catwoman kiss during a moment of truce while they are teaming up to take down a greater threat in Gotham. Maybe they are on a rooftop, surrounded by the chaos of the city below, and in that moment of shared purpose, their feelings surface and they share a passionate kiss.
One interesting plot could be that Batman and Catwoman team up to save Gotham from a new and powerful villain, and during their adventures, their feelings for each other deepen. They start to see beyond their usual cat - and - mouse game.
Another plot might be that Catwoman, as a yandere, tries to change Batman's identity. She thinks that his life as Bruce Wayne is what keeps him away from her fully. So, she devises plans to expose his secret identity, believing that once he's just Batman all the time, he'll be more devoted to her.
One possible plotline could be Batman and Catwoman's wedding being interrupted by one of their villains. Another could be them dealing with how to combine their very different lifestyles while married. Maybe they also have to face public scrutiny as Gotham's most unlikely couple.