Zeus is a possibility. As the king of the gods, he might see Percy's potential and adopt him to have an ally among the demigods. Another could be Poseidon, since Percy is already his son in the original story. It would be an interesting twist to have Poseidon formally adopt Percy in a more divine way.
Well, it could be about Percy having a new life in the realm of the gods. Maybe he gets special powers and training from them. He might also face new enemies that are threats to the gods, and he has to use his newfound abilities to protect the divine world.
Probably Poseidon, as he is Percy's father and has a vested interest in his son's well - being. Zeus might also be protective in some cases, despite their past differences, as Percy is a hero who often saves the world which benefits Zeus's realm as well.
Well, without reading the specific fanfiction, it's hard to say exactly who Percy is. But generally, in a 'champion of the gods' scenario, Percy would be a central figure. He might be a hero with unique powers, like being able to control certain elements or having superhuman strength. He could be a character who has to face various challenges and tasks on behalf of the gods, kind of like a chosen one in a fantasy story.
One great 'Percy Weasley Adopted' fanfiction is 'A New Family for Percy' on FanFiction.net. It explores how Percy's life changes when he's adopted into a different wizarding family. The story delves into his new relationships and how he adapts to their ways.
Zeus could be one. He is a powerful god in Greek mythology and might be interested in Harry's story. Another could be Odin from Norse mythology, known for his wisdom. And perhaps Isis from Egyptian mythology, as she has powers related to magic and protection.
The gods might show their protection in various ways. For example, they could directly intervene in battles Percy is in, using their divine powers to shield him from harm. They might also send him signs or omens to guide him away from danger.
Zeus is often one of the main gods showing possessiveness. He sees Percy as a powerful asset or a potential threat, so he wants to keep Percy in check. Poseidon, as Percy's father, also shows possessiveness in a different way. He wants to protect Percy but also use his powers for his own purposes sometimes.
Often, these fanfictions also explore the theme of loyalty. Percy has to decide where his loyalties lie - with his old life or his new adopted one. There can be a lot of internal conflict as he tries to balance these different aspects of his life, which makes for very interesting reading.
In Percy adopted fanfiction, the theme of discovery is quite common. He discovers new places, new abilities, and new secrets related to his adoption. Another frequent theme is acceptance. Percy has to accept his new situation, his new family, and sometimes even himself in a new light. And loyalty is also a theme. Whether it's his loyalty to his new family or his old friends, it often plays a role. For instance, in some stories, Percy has to choose between his old loyalties and the new ones that come with his adoption.