One idea could be a crossover where Lelouch, with his strategic mind, teams up with Harry and Percy to face a common magical - political threat. Maybe they have to infiltrate a powerful wizarding government that has been corrupted, and Lelouch uses his Geass ability to manipulate some of the key players while Harry and Percy use their magic and combat skills to fight off the guards.
A third concept could be that Lelouch, Harry and Percy are all transported to an alternate dimension. In this dimension, they have lost their memories but still retain their skills. They start to form a group as they sense a connection among them. As they journey through this strange land, they gradually regain their memories and realize that they were brought there for a specific purpose, like to stop an ancient evil that is about to be unleashed.
Another fanfiction could revolve around a tournament where all three are invited. It's a multi - dimensional tournament that tests not only their combat abilities but also their intelligence and morality. Lelouch might struggle with the moral aspects as his methods are often morally gray, while Harry and Percy have more straightforward views on right and wrong. They all compete against various opponents from different universes and in the process, learn from each other.
Perhaps a fanfiction where Lelouch uses his face as a tool in a negotiation with an enemy of the Black Knights. He manipulates his expressions to gain the upper hand, and the Black Knights watch in awe as he uses his face like a weapon in the diplomatic battle.
Well, a fanfiction could be where Milly has a special power that she has been hiding and she reveals it to help the Black Knights and Lelouch in a crucial battle. For example, she could have the power to manipulate time briefly, allowing the Black Knights to gain an advantage over their enemies.
The lemons could play a role in a magical fanfiction. For example, a lemon could have some sort of enchanted power that helps Nunnally see again if she's blind in the story. Lelouch then has to protect her and the lemon from those who would misuse the power.
You can start by looking on popular fanfiction websites like Fanfiction.net or Archive of Our Own (AO3). These platforms have a large collection of fanfictions featuring different characters, including Lelouch, Harry, and Percy. Just use their search functions and type in the relevant names to find stories that interest you.
The combination of different universes. Lelouch is from 'Code Geass', Harry from 'Harry Potter', and Percy from 'Percy Jackson'. When they are brought together in fanfiction, it creates a unique blend of magic, strategy, and adventure. For example, a story might have Harry's magic interacting with Lelouch's mind - controlling powers in a battle against some common enemy, while Percy uses his water - based powers to help them out.
One idea could be a story where Harry and Ginny are married and they take Gabrielle under their wing as a sort of apprentice in magic. Maybe Gabrielle is having trouble at Beauxbatons and they offer to help her improve her skills.
There are many great fanfictions that combine these elements. One common theme is crossovers where characters from Harry Potter and Percy Jackson universes interact in a world influenced by Godlingg. Writers often explore how the magic from Harry's world and the powers of the demigods in Percy's world co - exist and clash.
A fanfiction could be about a competition among Zeus, Poseidon and Hades, and Percy has to be the judge. The competition could be something like who can best help a small, struggling mortal town without using their full power. This would show a different side of the gods and also test Percy's ability to be fair and objective.
One idea could be that Lelouch, with his strategic mind, somehow gets transported to the Harry Potter world. He could use his Geass ability in a very different way, like influencing Death Eaters to turn against Voldemort. Another could be Harry Potter and Lelouch teaming up to fight a common enemy that has elements of both their worlds, perhaps a dark wizard who has also mastered some form of mind - control magic similar to Geass.
In a more adventurous fanfiction, Harry, Fred, and George are on a quest to find a lost lemon - colored magical creature. This creature is said to be able to grant wishes. Along the way, they face many obstacles like dark magic traps and unfriendly magical beasts. They rely on their combined skills and the power of friendship to keep going on their search.