Well, one plot device is the idea of the reader having some special ability or knowledge that attracts Snake. This could be something related to the supernatural elements in Black Butler. Also, misunderstandings are quite common. Maybe the reader misinterprets one of Snake's actions because of his quiet nature, which then leads to some drama and relationship development. And there's the classic 'fated encounter' plot, where it seems like the universe has brought the reader and Snake together for a specific purpose within the Black Butler setting.
In these fanfictions, a frequently used plot device is the introduction of a new threat or mystery that only the reader and Snake can solve together. It gives them a reason to bond and rely on each other. Another common one is the use of flashbacks, especially of Snake's life before meeting the reader. This helps in building his character and making the relationship between him and the reader more nuanced. Additionally, there can be a plot where the reader has to prove their loyalty to Snake in a world full of deception and danger, as is typical in the Black Butler universe.
Another theme is adventure. Since the Black Butler world is full of mystery and danger, many fics will have Snake and the reader going on adventures together. They could be exploring the dark alleys of London or trying to solve some mystery related to the Phantomhive household.
Well, in these fanfictions, the connection between Snake and the reader can be really diverse. Sometimes it's a slow - burn romance where the reader first has to gain Snake's trust, as he's quite guarded. His snakes can play a role in this too, either as a hindrance or a help. And the setting of Black Butler adds a layer of mystery and danger. The fanfiction might show how the reader adapts to this world while getting closer to Snake.
One common theme is adventure. The male reader often goes on exciting adventures with the Black Butler characters. Another theme is friendship or bromance, as the male reader forms strong bonds with the likes of Sebastian or Ciel.
One common theme is the power dynamic. Alois is a complex character with a lot of power in the 'Black Butler' universe, and fanfictions often explore how that power affects his relationship with the reader - insert character. Another theme is redemption. Some stories might have Alois seeking redemption through his relationship with the reader.
One common theme is the reader character being involved in the dark and mysterious world of the Black Butler universe. For example, they might be a new servant in the Phantomhive household and have to deal with all the supernatural events there.
One common theme is mystery. Undertaker is a very mysterious character, and this often seeps into the fanfiction. The reader is usually drawn into his world of secrets. Another theme is the contrast between the darkness associated with Undertaker and the possible light or innocence of the reader - character.
One common theme is mystery. Since the Black Butler universe is full of secrets, many fanfictions explore the mystery around Ash and how the reader gets involved in uncovering it. For example, the reader might be drawn into a plot related to Ash's past.
One common theme is loyalty. Pluto is a demon, and in many fanfictions, his loyalty to the reader character is explored. Another theme is discovery. Since Pluto has a unique nature, stories often involve the reader discovering more about him and his powers. Also, protection. Pluto may be shown protecting the reader from various threats in the 'Black Butler' universe.
Time - travel related to the future powers is also a popular plot device. The reader might be sent to the future or past due to their powers, and has to figure out how to get back or how to change things for the better. It's a great way to introduce different settings and versions of characters, and also allows for a lot of speculation about the future of the fandom's world.
Well, you can try looking on fanfiction platforms like Archive of Our Own. Search for 'Black Butler Snake x Reader' and then filter out the inappropriate or 'lemon' tagged ones. There are often many well - written, family - friendly stories that focus on the relationship between Snake and the reader in interesting ways, such as adventures they go on together within the Black Butler universe.