Percy would likely become more devious. Growing up with Loki as an adoptive father, he'd be exposed to Loki's tricks and lies. So instead of his straightforward, if sometimes impulsive, nature in the original Percy Jackson stories, he might think more about the different angles of a situation before acting.
One possible plot twist could be that Percy's demigod powers interact in unexpected ways with Loki's magic. Since Percy has control over water and Loki is known for his trickery, perhaps Loki uses Percy's powers to create illusions involving water, like making a dry desert seem like an ocean to deceive enemies.
In this fanfiction, there might be a lot of focus on Percy's relationship with the other wolves in Lupa's pack. He could learn their ways of survival, their hierarchy, and how to be a part of their community. This would be a great way to explore his adaptability and growth.
One possibility could be a story where Harry Potter, being the son of Loki, has a different set of magical abilities. He might be more mischievous like Loki and this could lead to some interesting interactions with the wizarding world. In this fanfiction, his encounter with Percy Jackson could be a clash of two different mythologies. Maybe they start as rivals but then realize they have to work together to face a common threat.
Well, of course, Percy Jackson himself often makes an appearance. He could be a mentor figure to the adopted son, guiding him through the ropes of being a demigod. Annabeth is also common, perhaps helping the adopted son with her wisdom and knowledge of the mythological world.
The setting of the story might shift a bit. Instead of always being at Camp Half - Blood or on quests related to the Greek gods, Percy could be in the territory of the wolves. There could be new threats and challenges there, like rival wolf packs or ancient enemies of Lupa. And all these elements would make for an exciting and different take on the Percy Jackson universe.
Well, if Percy was the son of Loki in a fanfiction, it would completely turn the Percy Jackson storyline upside down. Percy's powers would likely be a mix of his demigod abilities and Loki's trickery. His relationships with the other characters would also change. For example, his loyalty to Camp Half - Blood might be questioned as Loki is known for his duplicity. He could have a more mischievous side and might not be as straightforward in his actions as he is in the original stories.
Well, one possible plot could be Percy struggling to adapt to his new 'mother' Khione. He might have to deal with her cold and often unfeeling nature. For example, she could be trying to train him in her own ways which are very different from what he's used to at Camp Half - Blood. Maybe she wants him to use his powers in a more aggressive way to serve her own purposes.
One interesting plot could be the adopted son discovering his own unique powers that are different from the typical demigod powers in the Percy Jackson world. Maybe he has a special connection to an ancient and forgotten god, which leads to all sorts of adventures as he tries to figure out what it means and how to control it.
Well, it could be about Percy having to deal with the powers and heritage that come with being the adopted son of Pontus. Maybe he discovers new underwater abilities that are different from his Poseidon - given powers. He might also have to face enemies who are after the secrets Pontus has.