Often, it focuses on the intense relationship between Sebastian and another character. The 'lemon' aspect usually implies a more mature and passionate side of their relationship. For example, in many such fanfictions, there are detailed descriptions of their private moments together.
Well, Sebastian Michaelis is from 'Black Butler'. In his story, his relationship with Ciel is complex. It's not a typical romantic love but a bond of loyalty and a somewhat twisted connection. Sebastian is bound to protect Ciel due to their contract. However, there could be interpretations of a deeper, unspoken 'love' in the sense of his extreme dedication and the unique way he cares for Ciel.
The relationship in a sebastian michaelis x bardroy fanfic might also explore themes of loyalty and duty. Both characters are in service to the Phantomhive family in different ways. Sebastian's loyalty is a complex matter due to his demonic nature and ulterior motives, while Bardroy's loyalty is more straightforward. A fanfic could delve into how their different concepts of loyalty either clash or find common ground, perhaps when facing an external threat to the household.
You could start by looking on fanfiction.net. There are often a variety of fanfics in the Kuroshitsuji (Black Butler) section that might feature this pairing. Some popular ones are usually ranked higher, so they can be a good starting point.
Sebastian Michaelis x reader fanfiction often explores the relationship between the reader and the alluring Sebastian. It can range from romantic to platonic interactions. Some stories might focus on the mystery and charm that Sebastian has, while others could be about the reader getting caught up in the supernatural world he inhabits. It allows readers to insert themselves into the 'Black Butler' universe and have their own adventures with Sebastian.
Another theme is the struggle between his demonic nature and any emerging humanity. Some fanfictions show him experiencing emotions that are not typical for a demon, like compassion or love, and how he deals with that.
One common theme is the clash of different worlds. Since it's a crossover, Sebastian is often taken from his original 'Black Butler' world and put into a new one. So, you get to see how his demon nature and values interact with the new setting's norms.
I think it could be a very interesting and complex love story. Sebastian Michaelis is often depicted as a mysterious and alluring character. If there are 'broken wings' involved, perhaps it symbolizes a damaged or vulnerable aspect of one of the characters in the relationship. It might imply that they need to be healed or redeemed through love.
One possible fanfic could be about Sebastian falling in love with a human girl who is kind-hearted and brave. She might be a young noblewoman who is different from the typical spoiled aristocrats. Sebastian is initially intrigued by her uniqueness and as time passes, he starts to feel emotions he has never experienced before. Their relationship develops as they face various challenges together, like dealing with other demons who oppose their relationship or the strict social norms of the Victorian era.
Sebastian Michaelis' story has Ciel as a key figure related to what could be considered a love - like relationship. Since Sebastian is a demon bound by a contract to Ciel, his loyalty and the way he behaves towards Ciel, protecting him and being by his side constantly, makes Ciel the most likely candidate for a love interest in Sebastian's story, although it's a very different kind of relationship compared to traditional love stories.