One popular trope is the 'powerful outsider' where the OC has some extraordinary power that the main characters in Supernatural don't have, like the ability to control the elements. Another is the 'lost love' trope, where the OC has a past relationship with one of the main characters that ended traumatically. And the 'mysterious origin' trope is also common, where the OC's true nature or where they came from is a big mystery throughout the fanfic.
In Supernatural OC fanfics, the 'protective OC' trope is quite popular. The OC feels a strong need to protect the main characters from various threats. There's also the 'redemption arc' trope for OCs who have a dark past and are trying to make up for it in the Supernatural world. Additionally, the 'fated connection' trope, where the OC has a pre - determined connection with one of the main characters, either by fate or some supernatural force, is often seen.
There are also a lot of 'Alternative Universe' (AU) fanfics. These can range from modern AUs where the characters are in a completely different setting, like high school or a corporate office, to fantasy AUs where they might be in a magical world. These AUs give writers the freedom to explore different aspects of the characters' personalities and relationships outside of the show's canon.
One common trope is the 'hidden power' trope. The human OC often has some latent power that they don't know about until a crucial moment. Another is the 'outsider who becomes a hero' trope. They start as an ordinary human in the Bleach world but gradually rise to become important. And there's also the 'love interest of a main character' trope, where the OC ends up in a romantic relationship with someone like Ichigo or Rukia.
One popular trope is the 'Stranger to Lovers'. In Nyx and OC fanfiction, it often involves the OC being new to Nyx's world, and they gradually fall in love as they get to know each other better. For example, the OC could be a new recruit in a group where Nyx is a leader, and their relationship develops over time.
A common trope is the 'fish - out - water' situation. The OC, being from a different place or having a different background, has to adjust to Howl's strange and magical world. This can lead to humorous and heartwarming moments. Also, the 'protector - protected' trope is often seen. Howl, with his magic and skills, protects the OC from various threats, which in turn deepens their relationship. And then there's the 'redemption' trope. If the OC has some sort of flaw or past mistake, Howl can play a role in their redemption process.
One popular trope is the 'Power Struggle'. In bnha oc fanfiction, the original characters often face challenges in controlling or coming to terms with their unique powers. Another is the 'Friendship Overcoming All'. OCs form deep bonds with the canon characters and these friendships help them get through tough situations. Also, the 'Hidden Heritage' trope is common, where the OC discovers they have a special lineage or background that gives them an edge in the hero world.
A common trope is 'character crossovers'. Fans often write about the sisters from Charmed meeting Sam and Dean Winchester from Supernatural. It creates interesting dynamics as they have different ways of dealing with the supernatural. 'Time - travel' is another trope. Maybe a character from Supernatural travels back in time and meets the ancestors of the Charmed ones. And then there's the 'hidden family connection' trope, where it's revealed that there's some long - lost family tie between a character from Charmed and one from Supernatural.
Some popular tropes in Supernatural future fanfiction include the discovery of new dimensions. This can open up whole new worlds for the characters to explore and new threats to face. There's also the trope of a new generation of hunters emerging. These young hunters look up to Sam and Dean and try to follow in their footsteps. And a big one is the return of characters who were thought to be dead. It adds an element of surprise and nostalgia to the story.
One common trope is the forbidden love between a human and a supernatural being, like a vampire. Another could be the power dynamics in sexual relationships within the supernatural world, such as an alpha werewolf and his mate. Also, the idea of soulmates in a supernatural context often features in these fanfics.
A common trope is the mystery surrounding the incubus. In fanfiction, the incubus is often presented as an enigma, with its true motives and nature hidden. This keeps the reader guessing. Also, the idea of the incubus as a protector is popular. Despite their usually negative reputation, in some fanfictions, the incubus protects the human from other supernatural threats. Finally, the transformation trope can be seen, where the human character may start to take on some supernatural traits due to their association with the incubus.
There's the 'legacy' trope. The male OC could be related to a famous MCU character and has to live up to their name or break free from their shadow. For instance, he could be the son of a fallen hero. Another trope is the 'chosen one' trope. He's the only one who can defeat a certain big bad in the fanfic. And the 'mentor - mentee' trope, where he either mentors a younger character or is mentored by an established MCU hero like Captain America or Iron Man.