One common theme is the unspoken attraction between them. Their relationship in the games is full of mystery and tension, and fanfiction often delves deeper into that.
One common theme is trust. Since they often find themselves in precarious situations, the question of whether they can trust each other fully is a big part. For example, in many fanfics, Leon has to decide if he can trust Ada's motives.
One common theme is the struggle between love and duty. Leon and Ada are often on different sides in the official stories, so fanfics explore how their feelings for each other play out against their respective missions. For example, in many fanfics, Ada has to make a choice between helping Leon and fulfilling her own tasks.
Love and sacrifice are also prevalent themes. Since there's an obvious attraction between them, the concept of love is explored in different ways. Sometimes it's a slow - burning love, other times it's a passionate affair. And with love comes sacrifice. Fanfictions often put them in situations where they have to choose between their love for each other and their own self - interests or the greater good.
Hunnigan could be a great addition. She could provide Leon with information and support from the outside, and her presence could add some tension as she might be suspicious of Ada's motives. Another good character is Wesker. His past connection to Ada could create more drama and conflict in the story. He could be a shadowy figure trying to manipulate the situation between Leon and Ada.
Love in the face of danger is also a prevalent theme. Their jobs put them in constant peril, but that doesn't stop the development of their relationship. Fanfics often show how they find love and connection despite all the chaos and threats around them. It's a contrast that makes for very engaging reading.
One common theme is the danger and thrill of their relationship. Given the zombie - filled, post - apocalyptic world of Resident Evil 2, their love or attraction often has an edge of danger. Another theme could be secrecy, as Ada has her own motives and secrets, and Leon is often in the dark about some aspects of her.
One common theme is friendship. They often start from different backgrounds or even with some animosity, but gradually become friends through shared experiences.
Romance is also a big theme. Writers like to develop a romantic relationship between them, showing how their feelings for each other might have grown during their time together in the game's story. They might write about secret glances and unspoken feelings that gradually turn into love.
One common theme is adventure. Since both Leon and Sherry are characters from the Resident Evil universe which is full of danger and mystery, many fanfictions will have them go on adventures together, fighting against bio - horrors. Another theme is romance, of course. Writers like to explore the relationship between the two, how they might fall in love and support each other.
Survival is also a big theme. Given that they are usually set in a dangerous, post - apocalyptic world, they have to rely on each other to survive. This theme helps to build their relationship as they face threats from zombies or other villains.