A possible plot is that Si is a beta - tester of the game and due to a glitch, becomes OP. At first, Si enjoys the benefits like being able to defeat any monster easily or access restricted areas. But then, they realize that their OP status is causing imbalances in the game's ecosystem. So, Si has to embark on a journey to find a way to fix the glitch and restore balance to the game world, all while dealing with other players who are either jealous or want to take advantage of their situation.
One idea could be that Si, who was an ordinary person, suddenly gets transported into the game world and starts to gain OP (over - powered) abilities. For example, Si could have the power to control time within the game, allowing them to reverse bad decisions or speed up processes like leveling up. Another plot could involve Si being the only one immune to a powerful virus in the game world that is turning all the other characters evil, and they have to use their new OP powers to find a cure.
The most interesting aspect could be the power dynamics. Si, as an OP character, would change the existing power balance in the DxD world. They could challenge the traditional powerhouses and create new alliances or rivalries.
It could be the game's main boss character. Since Si has become OP, the main boss might see Si as a threat to its rule over the game world. So, it would do everything in its power to stop Si, whether it's by sending hordes of minions or using its own special abilities against Si.
Well, in DxD fanfiction, for Si to become an OP (over - powered) game character, it could be through some sort of magical or supernatural event. Maybe a glitch in the game world that sucks Si in and endows them with extraordinary powers. Or perhaps a powerful being within the DxD universe decides to transform Si as part of a grand plan.
One idea could be exploring what would happen if a minor character like Gendry had been secretly trained in magic. He could use his newfound powers to unite the smallfolk against the warring nobles. Another plot could revolve around a female knight from the North who disguises herself as a man to fight in the wars, and along the way, she discovers secrets about the White Walkers that no one else knows. Or perhaps a fanfiction where Daenerys and Sansa form an alliance much earlier and together they reshape the power dynamics of Westeros.
One idea could be a self - insert character who has the ability to communicate with the dragons on a deeper level. They could use this to prevent some of the tragic events in the series, like the destruction of King's Landing by Drogon. Another plot could involve the SI becoming a dragon rider and using their modern knowledge to train the dragon in new ways, for example, teaching it advanced aerial maneuvers.
A really interesting plot could be a time - travel fanfiction where a character from the modern world is transported to the North in the Game of Thrones universe. They use their modern knowledge, like basic science and different leadership ideas, to change the fate of the North. They could introduce new farming techniques or diplomatic strategies, which would create a whole new dynamic in the power struggles of the North.
Well, sometimes in 'naruto becomes op fanfiction', the plot twist is that Naruto's OP powers are not his alone. He discovers that he is sharing his body or mind with an ancient and powerful being. This being can take over at any time, and Naruto has to learn to co - exist with it. Also, there could be a plot twist where Naruto's new powers are the key to unlocking a hidden, dark past of the ninja world that no one wants to be revealed, and he has to decide whether to keep it hidden or expose it.
One plot idea could be that Si is a new student at Beacon Academy. They are in awe of Ruby and her skills. So, they start to follow Ruby around to learn from her. Along the way, they get involved in Ruby's adventures against the Grimm, and their own abilities start to develop as they face various challenges side by side with Ruby.
One interesting plot idea could be Percy having to team up with Artemis on a quest that involves an ancient artifact that has the power to disrupt the balance between the gods. Maybe it's an artifact that can control the tides in a way that endangers both land and sea. Another idea is a story where Artemis is somehow in danger and Percy has to use his skills and connection to the sea to save her while also dealing with her hunters who are initially suspicious of him. And a third plot could be about Percy and Artemis finding a new, unknown demigod who has powers that are a mix of the sea and the moon, and they have to figure out how to train this demigod and protect them from those who would misuse their powers.
One idea could be an OC with a unique sacred gear that has powers no one has seen before. For example, a sacred gear that can manipulate time on a small scale, allowing the OC to freeze time briefly during battles in Highschool Dxd's universe. This would add a whole new dynamic to the battles and interactions.