Well, perhaps the OC son of Orochimaru could be in a situation where he is forced to choose between following his father's evil ways or siding with the ninja world to stop Orochimaru once and for all. He could have a unique ability, say, the power to communicate with all kinds of snakes and use this to his advantage in battles or in diplomatic situations. He might also meet some old enemies of Orochimaru who initially distrust him but then come to see his potential for good.
Maybe the OC is an animal - shape - shifter who is being hunted for their rare ability. Orochimaru discovers the OC and instead of handing them over to the hunters, he decides to keep them under his protection in his lair. The OC initially hates Orochimaru but as they interact more, they realize that he's not as bad as the rumors say. This could be a story about acceptance, with the OC learning to trust Orochimaru and Orochimaru learning about the value of life from the OC.
One idea could be an Orochimaru crossover with the Harry Potter universe. Orochimaru could be a dark wizard from a far - off land who comes to Hogwarts seeking ancient magic. He might try to corrupt some of the students with his snake - like ways and thirst for power.
Perhaps the OC son of Doomsday is hunted by various groups who fear his potential. He has to constantly be on the run while also trying to discover his true origin and the purpose of his existence. He could meet a group of outcasts who help him hide and in return, he uses his powers to defend them.
One idea could be that the OC, as the son of Ozai, struggles with the dark legacy his father left. He could try to redeem his family name by using his firebending skills for good, like helping to rebuild the Fire Nation in a more just way.
One interesting idea could be Orochimaru seeing Naruto as a unique specimen and instead of just trying to use him, he actually starts to respect Naruto's willpower. This could lead to a strange mentorship of sorts where Orochimaru teaches Naruto some of his more unorthodox jutsu in exchange for Naruto trying to help Orochimaru find a new path that doesn't involve so much darkness.
How about a fanfiction where Orochimaru is transported to a different dimension where ninjutsu doesn't exist? He has to adapt and use his wits and knowledge in a completely new way. This would be a great way to explore his character without any adult themes. Or a story where Orochimaru tries to atone for his past sins by helping to rebuild a village that he once destroyed, showing a different side of his complex character.
Perhaps a plot where the Oc is on a quest to discover more about his mother, Ophis. Along the way, he forms unlikely alliances with both friends and foes, and has to navigate through various dangerous situations. For example, he could be seeking ancient artifacts related to Ophis that are scattered across different realms. This would lead him to encounter different cultures and powers within the supernatural world.
One idea could be the OC's struggle to prove himself worthy in the eyes of his father, Stannis. He might face challenges like being overshadowed by his father's more well - known followers. Another plot could involve the OC getting involved in the power struggles of Westeros, trying to uphold his father's claim to the Iron Throne while also forging his own path. Maybe he discovers a hidden secret about his family that changes everything.
One plot idea could be the OC's struggle to live up to his father Hephaestus' reputation. He might face challenges in creating unique and powerful artifacts, while also dealing with the expectations of the other gods. Another could be a quest to retrieve a lost, powerful weapon made by Hephaestus that only his son can sense. The OC could also get involved in a love story where his skills as a son of Hephaestus play a role, like creating a special gift for his beloved.
One idea could be that the OC has to deal with the legacy of Black Widow. He might struggle with living up to her name while also trying to carve out his own identity in the superhero world.