One plot idea could be that the male demon OC is sent to disrupt the quest of the hobbits. He tries to steal the One Ring for his own dark purposes. Another idea is that he forms an unlikely alliance with the hobbits. Maybe he realizes that by helping them, he can gain something in return, like a way to redeem himself. Or perhaps he is in search of a lost relic in Middle - earth and his path crosses with the hobbits, and they end up having to cooperate to find it.
Well, consider a plot where the male demon OC is actually a fallen hero from a different time. He was corrupted by dark magic and turned into a demon. The hobbits, with their pure hearts, start to influence him to turn back to his former self. Or there could be a plot where he is in a power struggle with another demon in Middle - earth. The hobbits get caught in the middle of this struggle. He might use the hobbits as pawns at first, but then starts to care for them as the story progresses. Additionally, he could be the one who reveals a long - forgotten prophecy to the hobbits that changes the course of their adventure.
A good plot could involve the male elf OC being sent on a mission by his elven king to spy on the dwarves' journey. But during this, he realizes that the dwarves are not as bad as he thought and decides to help them instead. He could also be cursed by an evil sorcerer, and the only way to break the curse is to complete a series of impossible tasks. This could lead him to team up with unlikely allies, like a hobbit or a wizard. Additionally, his family's past could come back to haunt him, and he has to face his ancestral demons to save his people.
A great plot could be that the male OC has a past connection to one of the main Avengers villains. For example, he was experimented on by the same organization that created the Hulk. This leads to a complex situation where the Avengers don't know if they can trust him. Or, the male OC could accidentally time - travel and change a small event in the past that has major consequences for the present - day Avengers, and he has to fix it.
One plot idea could be that the male OC discovers a hidden vampire society within Mystic Falls that has been kept secret from the main characters. He then has to decide whether to reveal it to them or keep it a secret for his own gain. Another idea is that he falls in love with a human girl, but she is being hunted by a powerful vampire hunter. He has to protect her while also hiding his true nature from her.
A good plot could involve the male OC finding a cure for the walker virus (even if it's just a false lead at first). He becomes obsessed with it, and this drives his actions and relationships. Or perhaps he is wrongly accused of stealing from his group, and he has to prove his innocence while also dealing with the external threats of the apocalypse.
An OC could be a wizard - in - training from a far - off land who has heard of Gandalf and wants to learn from him. They tag along with the dwarves and Bilbo, bringing their own brand of magic which is different from Gandalf's. Maybe their magic is more nature - based and they can control plants to create barriers or bridges when needed.
For a male OC in The Hobbit fanfiction, consider names like Eamon, which means 'wealthy protector'. It gives the idea that he might be there to protect the group on their journey. Then there's Lior, which means 'my light' in Hebrew. It could imply that he brings hope or guidance. Also, the name Faelan, which means 'little wolf', can suggest a fierce and loyal nature.
For an Inuyasha male OC fanfiction plot, consider this. The male OC is an artist who can paint things that come to life. He gets caught up in the chaos around the Shikon Jewel when one of his paintings accidentally becomes a powerful demon. Now he has to work with Inuyasha and the others to defeat it. Or he could be a demon slayer who has a personal vendetta against a particular type of demon that is also involved in the Shikon Jewel saga. His presence disrupts the group's dynamics at first, but they soon realize they need his skills. Another idea is that he's a messenger from another dimension who brings news of a greater threat that will affect not only the Inuyasha world but also other dimensions.
One plot idea could be that the male OC is a detective hired to investigate strange disappearances in the Black Butler world. He starts to suspect that there's a supernatural force at work and teams up with the main characters to solve the mystery. Another idea is that he's a nobleman's son who has a secret identity as a vigilante, fighting against the corrupt nobles. He might cross paths with Ciel and Sebastian when they're on a mission related to the same nobles.
A plot could involve the male OC being related to one of the scientists who worked at the lab. He comes to Hawkins to find out what really happened to his relative. Along the way, he teams up with the kids and they uncover a conspiracy that goes deeper than they thought. Or perhaps the male OC is an artist and he starts having visions of the Upside Down through his art, which leads him on a journey to figure out what they mean.
Perhaps the dragon OC has the ability to transform into a human - like form. It infiltrates the company of dwarves and hobbits, initially with some ulterior motive. But as the journey progresses, it starts to care for them and uses its dragon powers secretly to aid them against various perils, creating a lot of mystery and suspense in the fanfiction.