Well, 'body merge fanfic' often refers to fan - made stories. In these stories, the merging of bodies can happen for various reasons. It could be due to a magical spell gone wrong in a fantasy - based fandom, or some sort of scientific experiment malfunction in a sci - fi related one. For example, if it's a fanfic based on a superhero franchise, two superheroes might merge bodies and then have to deal with the consequences like learning to control their new combined powers and dealing with how their friends and foes react to this new entity.
Well, start by creating a strong setup. Let the readers know the situation of the characters before the possession. When writing about the merge, use vivid descriptions. For example, you can write about how the thoughts of the two entities start to swirl together like a tornado in the mind of the possessed. Develop the relationship between the two entities during the merge. Are they enemies who learn to cooperate? Or are they friends who become even closer? And make sure to have a satisfying ending, whether it's a complete merge or a separation of the entities.
There are also 'body possess merge fanfic' in the science - fiction realm. For instance, an alien entity might possess a human body in order to survive on Earth. As the merge occurs, the human and alien start to share memories and skills. This can create a complex web of relationships and power dynamics, especially if there are other characters involved who are either trying to help or stop the merge.
There could be a 'body merge fanfic' in the Lord of the Rings universe. For example, an elf and a dwarf might merge bodies due to some ancient magic that was misused. In the Doctor Who fandom, perhaps the Doctor and one of his companions could merge bodies as a result of an encounter with a strange time - space anomaly. And in a Final Fantasy fanfic, two characters from different races like a human and a moogle could merge bodies, which would lead to a really unique and comical story as they try to navigate their new combined form in the game's world.
In fanfic, it could be through a dark spell gone wrong. Maybe a spell that was meant to destroy the Horcrux instead backfired and caused it to merge with Harry.
In some fanfics, if a Horcrux were to merge with Harry, it could potentially give him some of Voldemort's powers. But it would also likely be a great struggle for Harry's soul. He might have to constantly fight the dark influence within him.
In a merged world, the power structures would change. The Gems, who are used to being the protectors of Earth in their world, would now have to share that role with Ben. Ben's aliens could provide new ways to defend the planet, while the Gems' magic could offer solutions to problems that Ben's aliens couldn't handle alone. Also, the villains from both worlds might team up, forcing Ben and Steven to form a united front. They would need to combine their powers, like Ben using an alien form that could enhance Steven's powers, or Steven using his powers to boost an alien's abilities.
Their worlds could merge through a magical portal. Maybe a powerful jutsu in Naruto's world accidentally creates a rift that connects to Bayonetta's dimension. This would allow characters from both sides to interact.
In the end of the fanfic, Harry Black's merged bloodline could lead to him forming new alliances. His unique bloodline makes him an interesting figure to different groups. Some might see him as a threat, but others recognize the potential benefits of allying with him. Through these new alliances, he is able to achieve a greater goal, like unifying different factions that have been at war for ages. His bloodline gives him the charisma and the abilities to make these alliances work and finally bring peace and stability to the land.
The merging could also happen due to a powerful artifact. Suppose there is an ancient artifact in Skyrim that has the power to connect different realms. If it gets activated, it could pull the world of Game of Thrones into Skyrim's universe. Then, the political intrigue of Game of Thrones, like the power struggles in King's Landing, could be introduced to Skyrim's cities. The Nords in Skyrim would have to deal with the complex politics of the Seven Kingdoms.