Perhaps a human character who is drawn to Regina's allure despite knowing she's a vampire. This human could be brave and try to understand her world, and they could fall in love over time as they face various challenges together.
It could be another vampire. Maybe a powerful and mysterious male vampire who is both her rival and her love interest. Their relationship could be full of passion and conflict.
Another option could be a character from a different fictional universe in crossover fanfictions. For example, a character like Jack Frost from Rise of the Guardians. Writers might bring these two together because they both have powers related to ice and snow, and it could make for an interesting dynamic as they explore their powers together and develop feelings for each other.
In some fanfictions, Lloyd might develop feelings for Kai's sister, Skylor. Given their interactions in the series, it's not a far - fetched idea. Their relationship could be built on mutual respect and admiration, and in the fanfiction, it could evolve into a deeper romantic connection.
Another possibility is Kyosuke. In the original story, Madoka had some feelings for him. In this fanfiction, they could explore a deeper romantic connection, perhaps with some twists and turns that are different from the original plot.
Irene Adler could be a great love interest. She's smart, cunning, and was able to outwit Sherlock once. Their relationship in the original stories had a certain tension that could be developed into a full - blown love story in a fanfiction. She challenges him and has her own secrets, which could make for an exciting dynamic.
Sasori could be an interesting love interest. They are both from Akatsuki and have a certain connection through their art, though Sasori's is more in the form of puppets and Deidara's is explosive art. Their different personalities could create a lot of tension and a unique love story.
A foreign ninja from another village might also work well. This ninja could bring a different perspective to Kabuto's world. They could meet during a diplomatic mission or a joint training exercise between villages. Their love would be a bit more challenging as they have to deal with the politics between their respective villages, but it would add an interesting layer to the fanfiction.
A strong - willed priestess could be a great love interest. She could be the one who interprets the gods' will and at first is hesitant about Hercules due to his half - god status, but then falls for his heroism.
A possible love interest could be another Autobot. Maybe a female Autobot with whom he has fought side by side for a long time and gradually developed feelings for. Another option could be a human female who has shown great courage and understanding, and through their interactions, Optimus Prime finds himself attracted to her.
The love interest could be a young nurse traveling to America to start a new job. She has a caring nature, which attracts Officer Lowe. During the rescue operations, she helps the injured, and Lowe is impressed by her skills and compassion.
It could be a new female character introduced in the fanfiction. She could be a strong beyblade fighter herself, with a fiery spirit that matches Kai's. This would make their relationship full of competition and passion.