Another theme is the relationship between characters. The 'bodyheat' can be a metaphor for the closeness and intimacy (not necessarily in a romantic way) that develops between survivors. They are forced to be close to each other, and this can lead to complex relationships.
Fear is also a prevalent theme. The idea of being in close proximity (the 'bodyheat' situation) with a potential threat, like a zombie or a bio - weapon, adds to the sense of fear. Fanfics play on this by creating tense situations where characters have to deal with both the physical closeness and the danger at the same time.
Some 'bodyheat resident evil fanfic' might involve the villains as well. For instance, a fanfic could depict a scenario where a captive has to deal with the 'bodyheat' of a menacing Nemesis - like figure in a confined space. This creates a very different and often dark and suspenseful atmosphere in the fanfic.
One common theme is the clash of two different universes. The bright and colorful world of Pokemon colliding with the dark and dangerous Resident Evil world. Another theme could be survival, just like in Resident Evil, but now with the added element of Pokemon. For example, trainers and their Pokemon having to fight for their lives against bio - threats.
Survival is a common theme. Given the nature of the Resident Evil 2 world, Sherry often has to fight to survive in fanfics. Another theme could be her growth as a character, from a young and somewhat vulnerable girl to a more capable and strong individual.
Survival is also a major theme. The characters in both Resident Evil and Hellsing are constantly in life - threatening situations. In fanfics, this often leads to some intense and harrowing scenes. They might be trapped in a zombie - infested area from Resident Evil while also dealing with the dangerous vampires from Hellsing, and the characters have to use all their skills and resources to stay alive.
Protection is a common theme. Leon is often portrayed as Ashley's protector, and this dynamic forms the basis of their relationship in the fanfics. Another theme is growth, as both characters grow from their experiences together.
The theme of redemption often pops up too. Maybe a character from another franchise who has made mistakes in their own world gets a chance to redeem themselves in the Resident Evil 6 crossover. Or a Resident Evil character has a chance to make up for past failures by working with new allies from the crossover. It adds depth to the characters and the overall story.
One common theme is survival. Female characters often have to fight for their lives against the various bio - threats in the Resident Evil universe. Another theme is empowerment. They show that women can be just as tough and resourceful as men in these terrifying situations.
Survival is a very common theme. Just like in the original 'Resident Evil 2', when characters from different universes cross over, they still have to fight to survive the zombie - infested Raccoon City or deal with the bio - weapons.
Survival is a very common theme. Since Resident Evil is about surviving in a world full of bio - horrors, when crossed over with other universes, the characters often have to adapt and survive in new and even more dangerous situations.
One more common theme is the exploration of relationships. It could be a friendship or a more romantic relationship between Alice and the OC. They might start off as strangers and gradually develop a deep bond as they face challenges together. Also, the theme of redemption can be present. Maybe the OC has a past they are not proud of and through their adventures with Alice, they seek redemption.