The story could be full of adventure. Percy, as Rhea's adopted son, might have access to a whole new level of power and knowledge. He could be involved in ancient prophecies and battles that are directly related to the Titans. Maybe he'd use his newfound status to protect Camp Half - Blood in a different way, perhaps by making alliances with the Titans that others wouldn't dare to.
He might have the power of earth manipulation. Since Rhea is associated with the earth, Percy could gain the ability to control the ground, like creating earthquakes or forming barriers made of stone. This would be a very powerful addition to his existing powers.
One possible plot could be Percy's discovery of his true parentage as the son of Kronos and Rhea. This could lead to a huge power struggle within the demigod world. Other gods and demigods might fear his potential power and try to either eliminate him or recruit him to their side.
The Titans who don't want Rhea to gain more power through Percy could be antagonists. Kronos, for example, might see Percy as a threat to his own plans for domination.
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.
Yes, there might be. The Percy Jackson fandom is quite large and diverse, and fanfiction writers often come up with all sorts of creative pairings. However, the idea of Percy marrying Rhea is rather unusual as Rhea is a very powerful and ancient goddess in Greek mythology and Percy is a demigod. To find such a fanfiction, you could try searching on popular fanfiction websites like Archive of Our Own or FanFiction.net.
One idea could be Percy discovering his connection to Rhea in a dream. Then, he starts to have strange powers related to her that he has to figure out how to control.
Percy would likely become more conflicted. His previous identity as the son of Poseidon shaped his values and actions. But as the son of Kronos and Rhea, he'd have to reevaluate everything. He might become more cautious, as he now represents a more controversial lineage.
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.