Well, there's the 'unexpected - attraction' trope. It could be that Spider - Man initially has no intention of being in a harem - like relationship, but the other characters' unique qualities draw him in. The 'rival - turned - ally - in - love' is also seen often, where a character who was once an enemy or rival becomes part of the harem. And then there's the 'group - mission - bonding' trope, where going on missions together as a group makes the relationships in the harem stronger.
One popular trope is the crossover aspect itself. Writers often like to bring the characters from Spider Man and Vampire Diaries together in unexpected ways. For example, having Spider Man face off against the vampires in Mystic Falls. Another is the 'fish out of water' trope, like if Peter Parker somehow ended up in the Vampire Diaries' universe and had to adapt to its rules.
The 'team - up' trope is always popular. Whether it's Spider - Man teaming up with Deku and his friends to take on a powerful villain, or the MHA heroes joining Spider - Man to fight a threat in New York. Also, the 'mentor - mentee' trope can work well. Spider - Man could mentor a young hero in MHA, teaching them about responsibility and using their powers effectively.
One common trope is the 'outsider becomes central' where the main character, often an original character in the fanfic, is suddenly in the middle of a group of Hogwarts students who form a sort of harem. For example, a new student from a different magical school might come to Hogwarts and attract the attention of Harry, Ron, Hermione and others in a romantic or platonic way that builds a harem - like dynamic.
The 'rivalry - turned - love' trope is also common. Some female characters start off as rivals to Naruto in terms of power or goals, but then gradually develop romantic feelings for him. Like Sakura might initially be more focused on Sasuke, but in the fanfic, she realizes Naruto's true worth and falls for him.
One common trope is the 'fish out of water' where the main boy enters a new world full of different male characters vying for his attention. Another could be the 'slow burn' relationship development among the characters in the harem.
A common trope is the 'fish - out - of - water' story. For instance, if Spider - Man ends up in the My Hero Academia world, he has to adjust to the different rules and social norms. He might be confused by the concept of 'quirks' at first. Another trope is the power - exchange trope, like I mentioned before, where a character from one universe gets the powers of the other. It's always interesting to see how they adapt to it.
Some 'Spider Man Harem Romance Fanfiction' stories are really creative. They take the existing Spider Man lore and add this unique harem romance aspect. One such story could be where Spider Man accidentally creates a situation where multiple women think they are in a relationship with him. This leads to all kinds of comical and romantic situations as he tries to sort things out. And then there are those that delve deeper into the emotional connections between him and the women in the harem, exploring themes of loyalty, jealousy, and true love within this unconventional setup.
Well, a popular trope is the 'love triangle' within the harem. Even though it's a harem, there might be a more intense connection between Link and two of the harem members, creating drama. Also, the 'shared adventure' trope. Link goes on adventures and the harem members are part of those adventures, strengthening their bonds. And there's the 'rivalry within the harem' where members might compete for Link's attention in different ways.
The 'fish - out - of - water' trope is quite popular. Since Spider - Man is from New York and Wakanda is a very different place, seeing him struggle to understand Wakandan customs while Shuri finds his confusion both amusing and endearing. For example, when he first tries Wakandan food or attends a Wakandan ceremony.
One popular trope is the mentorship. Since Spider - Man has a connection with Tony Stark in the movie, fanfictions often expand on this. Another is the 'fish out of water' trope where Spider - Man is out of his comfort zone when dealing with the Avengers' big - scale operations.