One popular trope is the overprotective yandere. In yandere harem fanfiction, this character is extremely possessive of the main character and will go to great lengths to keep others away. Another trope is the rivalry among the harem members. They often compete for the main character's attention, which can lead to some intense and dramatic scenes. Also, the 'damsel in distress' scenario where the main character is constantly in need of protection from the yandere or other threats is quite common.
Harry Potter is obviously a central character. Then there could be female characters like Hermione who might take on yandere traits in the fanfiction. Also, characters like Ginny Weasley could be part of the harem with yandere - like behaviors towards Harry.
There's 'Percy and His Harem of Devotion'. It shows how Percy's yandere tendencies create a complex dynamic within the harem. Each character in the harem has their own unique relationship with Percy, and the fanfiction explores how they all interact in the face of Percy's overbearing love.
A different concept could be that a yandere curse is placed on Naruto, and as a result, any girl who gets close to him starts to develop yandere traits towards him. This could lead to a really chaotic harem situation where the girls are constantly fighting over Naruto, and Naruto has to figure out how to break the curse while dealing with their over - the - top affections.
It could be a fan - made story that combines the Naruto universe with the concepts of harem (where one character is surrounded by multiple love interests), heaven (maybe a positive or ideal setting), and yandere (a character type that is overly possessive and often violent in love). However, without reading it, it's hard to say precisely.
For the yandere character, give them a complex backstory. Maybe they had a traumatic experience in the past that led to their yandere tendencies. For the harem members, vary their personalities. One could be a bookworm, another a jock. Also, give them unique goals and desires related to the main character. For example, one might want to protect the main character's innocence while another wants to help them achieve their dreams.
In some plots, the yandere elements add a lot of drama to the story. For instance, there could be a love triangle within the harem where two yandere characters are vying for Harry's attention. This could lead to all sorts of magical mayhem. One might try to use a love potion on Harry while the other tries to counter it with their own magic, all while Harry is in the middle, completely oblivious to the full extent of their 'yandere' natures.
Maybe a powerful and mysterious force affects the minds of some RWBY characters, turning them into yanderes for a particular character. This could lead to a lot of drama as they try to keep their yandere tendencies hidden while also vying for the object of their affection. For example, Ruby could be affected and her normally innocent nature takes on a more possessive and obsessive side when it comes to the person she loves.
Popular themes in this type of fanfiction might include the protection of the main character by the harem members. Given Naruto's world of battles and danger, the harem could be seen as a source of support. The yandere theme can introduce the idea of over - protection, which sometimes turns into a form of control. Another theme could be the discovery of true love within the chaos of the harem and the yandere - induced problems. It's about how the characters navigate through this complex setup of relationships, with the added spice of the Naruto - related elements like ninjutsu and the ninja world's values.
Yang could be a likely candidate. She's strong - willed and passionate. If she fell into a yandere state, she'd be very protective and possessive. Blake is also a possibility. Given her past and her somewhat reserved nature, if she developed yandere tendencies, she might be more subtle about it but equally as intense.