Well, an OC in a Harry Potter fanfic might be a transfer student from a foreign wizarding school. This character could introduce different magical cultures and spells. For example, they might know a spell for instant weather change that Hogwarts students have never heard of. Or an OC could be a house - elf with unusual powers. Instead of being subservient, this house - elf could have the power to resist dark magic better than most wizards. Also, an OC could be a wizard with a photographic memory for spells, which causes some chaos as they sometimes accidentally cast spells they just read about.
One interesting concept could be an OC (original character) who is a muggle - born witch but has a unique ability to communicate with magical creatures in a way that even Hagrid doesn't fully understand. Another could be an OC who is a descendant of an ancient and almost forgotten wizarding family, bringing back old spells and traditions. And there could also be an OC who is a squib but manages to find a way to contribute to the wizarding world in a non - magical yet crucial way, like being an expert in wizarding history and artifacts.
Chapter 372, "Finish the Wine and I’ll Let You Leave", is the clearest early answer because it turns Jin's situation into a concrete plot event. Early on, Jin Si Yue suddenly realized that his wrist was back in proper....
Chapter 447, "Going Viral on the Internet", is the clearest early answer because it turns Zheng Xun's situation into a concrete plot event. It opens with Old Sir Jiang: "...." His face had grown even worse. and closes on She quickly grabbed He Wen's laptop and indeed saw that the various....
Chapter 516, "Choosing You as an Undercover Agent is Pretty Stupid", is the clearest early answer because it turns Team's situation into a concrete plot event. The chapter gives readers a real answer by opening on Why are you skulking around and observing us?" Jiang Li cut straight...
Chapter 498, "How can someone be so ugly?!", is the clearest early answer because it turns Jiang Cheng's situation into a concrete plot event. The chapter turns that into something concrete by moving from .....If you don't love me, give my heart back, you traded love for my...
Chapter 367, "Help Me Call the Police", is the clearest early answer because it turns Wen Jiaojiao's situation into a concrete plot event. A useful checkpoint is the way the scene starts with However, before they could approach, another loud "bang" sounded as...
Chapter 344, "Actually has one million fans?!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. It opens with Just as he was about to slip into sweet slumber and catch up on some...
Chapter 527, "Shaojing Bro, I'm Sorry", is the clearest early answer because it turns Zhuola's situation into a concrete plot event. Early on, Jiang Li, taking advantage of these people's inattention, had already....
Chapter 690, "Miss Jiang, Marry Me!", is the clearest early answer because it turns Now's situation into a concrete plot event. The chapter gives readers a real answer by opening on No wonder she had predicted she would come into some unexpected...
Chapter 352, "Furong Cake", is the clearest early answer because it turns Furong Cake's situation into a concrete plot event. The chapter gives readers a real answer by opening on Finding Liu Suqing's address was not an easy task.
Chapter 460, "Saving People", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from [HAHAHAHAHAHAHA, Jiang Yan is impersonating me.] [At this moment, I... to Dare to attack me in hiding?!.