In my love story anime fanfiction, some great tropes to use include the 'childhood friends to lovers' trope. It gives a sense of history and familiarity between the characters. The 'rescue the damsel/dude in distress' trope can also add some drama and a chance for the hero/heroine to show their feelings. Also, the 'unrequited love' trope can create a lot of emotional tension, especially if the unrequited love is eventually reciprocated in an unexpected way.
One popular trope is the 'tsundere' character. This is a character who is initially cold or hostile but warms up over time. Another is the 'opposites attract' concept, where two very different characters fall in love. And the 'love at first sight' trope is also common.
One popular trope is the 'accidental harem' where the protagonist unknowingly attracts multiple love interests. For example, in many school - set anime fanfictions, the main character's kind nature or unique talent draws in different characters of the opposite sex. Another is the 'harem competition' where the love interests compete for the protagonist's affection, often leading to humorous and dramatic situations. Also, the 'protective harem' where the members of the harem work together to protect the protagonist from external threats is quite common.
One popular trope is the 'hidden identity' trope. For example, your OC could be a powerful vampire who has been hiding their true identity from the Mikaelson family for years. Another is the 'love triangle' trope. Your OC might be caught between two main characters, like being in love with Klaus but also having a strong connection with Elijah. The 'fish out of water' trope is also great. If your OC is a new werewolf in the French Quarter, they will be out of their element dealing with the complex politics and power struggles there.
The 'reunion' trope is also popular. After a long time apart, perhaps due to the end of the summer, the characters reunite and rekindle their love. And the 'love triangle' trope can add drama. For example, a character may be torn between two potential lovers during this summer of love.
One popular trope is the relationship between a soldier and their commander. It adds an element of forbidden love or a power dynamic. For example, a rookie falling in love with the battle - hardened commander.
One popular trope is the 'enemies to lovers' situation. In this, the two main characters start off disliking each other but gradually fall in love as they get to know each other better. Another is the 'forbidden love' trope, perhaps due to different social statuses or family feuds. The 'love triangle' is also common, where one character has feelings for two others and has to make a choice between them.
In Highschool DxD OC fanfiction, the 'Power - Up' trope is quite common. Your OC starts with a certain level of power and then, through training, battles, or special encounters, they gain more power and become stronger. The 'Redemption' trope can also be used. If your OC has made mistakes in the past or has a dark history, they can strive to redeem themselves throughout the story. Also, the 'Chosen One' trope works well. Your OC could be the one chosen to save the supernatural world from a great threat, like an impending war between devils, angels, and fallen angels. This gives them a sense of purpose and importance in the story.
One popular trope is the 'enemies to lovers' trope. The OC and Rayla could start off on the wrong foot, perhaps having different goals or misunderstandings. But as they are forced to work together, they begin to see the good in each other. Another is the 'fish out of water' trope, where the OC comes from a different background than Rayla, and has to adapt to her world, creating humorous and heartwarming situations along the way.
One popular trope is the 'fish - out - of - water' for the OC. For example, if the OC is from a different dimension or has just discovered their powers. They'll be out of their depth in Power Girl's world at first. Another is the 'unlikely alliance' where the OC and Power Girl have to team up despite initial differences. And of course, the 'love interest' trope can also be used, but it has to be done carefully so it doesn't overshadow the main superhero aspects.
In For Honor OC Faction Fanfiction, the 'mentor - student' trope is quite common. An experienced OC could be mentoring a younger, more inexperienced one within the faction. The 'rebel within the faction' trope is also popular. An OC might oppose the traditional ways of the faction and try to bring about change. Also, the 'treasure hunt' trope can be used. The OC faction could be on a quest to find a powerful, ancient artifact that could change their fate.
Some great tropes for Bleach female OC fanfiction are the 'chosen one' trope. Your character could be chosen by some ancient power to save the Soul Society. The 'fish out of water' trope is also good. If your OC is from a different dimension or realm, she'll have to adjust to the Bleach universe. And then there's the 'redemption arc' trope. Maybe she was once a bad guy but is now trying to make amends. These tropes can add depth and familiarity to your story.