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.
Another possible power is the ability to communicate with ancient beings. Rhea has a long history, and Percy, as her adopted son, could be able to talk to the spirits or entities that have been long forgotten. These beings could offer him advice, knowledge, or even hidden powers that no one else has access to.
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.
His physical strength might increase. Thor is known for his great strength, and as his adopted son, Percy could inherit some of that. He might be able to lift heavier objects or fight more powerfully in close - combat situations. Maybe he could even hold Mjolnir for a short period of time, which would be a huge boost to his powers and status in both the Greek and Asgardian worlds.
His powers could become more ice - related. Since Khione is the goddess of snow, Percy might gain the ability to freeze water instantly. For instance, instead of just controlling water, he could turn it into ice sculptures or use ice as a weapon, like creating ice shards to throw at enemies.
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.
His powers might become more related to Hera's domain. For example, he could gain some control over marriage and family bonds. He might be able to sense when relationships are in trouble or strengthen the loyalty between people. Also, his existing powers could be enhanced in a way that reflects Hera's influence. Maybe his water - based powers could be more refined and have a new aspect to them, like being able to purify water to heal emotional wounds as well as physical ones, since Hera is associated with purity in some ways.
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.