His water - based powers might be more intense. Since he's directly related to Poseidon, he could have greater control over large bodies of water, like being able to create huge tidal waves with just a thought, instead of just small ones. He might also be able to communicate with sea creatures on a deeper level, understanding their complex languages and using them to his advantage in ways he couldn't before.
If Percy is fanfictionally the brother of Poseidon, his powers could extend to the realm of underwater architecture. He might be able to construct elaborate palaces or fortresses underwater using just the water and minerals in the ocean. Also, his healing abilities related to water could be more potent. Instead of just using water to heal minor wounds, he could potentially bring someone back from the brink of death by submerging them in a special pool of water he creates with his powers. His powers would be on a whole new level compared to his normal demigod state.
Well, if Percy was the son of Loki and Poseidon in fanfiction, his powers would be a really wild mix. He might have Poseidon's control over water, but with a Loki - like trickster twist. For example, he could create illusions in the water, making it seem like there are sea monsters when there are none to deceive his enemies. He could also use Loki's shape - shifting ability while in the water, perhaps turning into a mermaid - like form with a mischievous glint in his eyes. His power over water could also be used in more devious ways, like creating whirlpools that suck in his foes and then spit them out in a different location, all while laughing like Loki would.
If Percy were the son of Poseidon and Hera, his powers would be quite unique. His water powers could be enhanced in a different way. Maybe instead of just controlling water, he could transform water into different substances related to Hera's domain, like turning water into a fertile soil - like substance for plants to grow. His leadership skills would be off the charts. He could use his Poseidon - given strength and Hera - influenced charisma to lead not just demigods, but also other mythical creatures. He might also have the power to protect a place or a group of people in a more profound way, like creating a shield made of both water and a golden energy that represents Hera's protection.
In a fanfiction where Percy is the son of Hades and Poseidon, his powers would be truly extraordinary. He could have the ability to create portals in water that lead to the Underworld. This would give him an advantage in both battle and travel. His hydrokinesis could be tainted with the essence of death, so when he attacks with water, it could cause a draining effect on his opponents, sapping their life force. Additionally, he might be able to sense the presence of the dead in any water source, which could be used for both reconnaissance and protection.
Well, in the original Percy Jackson stories, Percy has powers mainly related to water as the son of Poseidon. But in this fanfiction with Hestia as his mother too, he might have an added connection to fire or the concept of home. So, he could potentially have the ability to control the temperature of water, like making it boil or freeze instantly, which combines his water powers with a bit of the hearth - related powers. He might also be able to create a sort of protective shield around himself and his friends that has the properties of both the ocean's strength and the warmth and safety of the hearth.
Well, instead of summoning water or having a connection with the sea, he might have the power to shift shapes, a common ability associated with Loki. He could turn into different animals or even other people to gain an advantage in a fight or to infiltrate an enemy's stronghold. Also, his power over fire could be enhanced, as Loki has some association with fire in Norse mythology. He could use this to create distractions or attack opponents from a distance.
His powers would likely become more god - like. He might gain the ability to control lightning, like Zeus. Also, his strength and speed could be enhanced to a much greater degree. His control over water, which was his main power before, could also be amplified and perhaps combined with his new lightning powers in some unique ways.
Percy's powers would be more complex. He could have the ability to communicate with sea deities in a different way. Maybe he could use Hera's diplomatic skills to make deals with them or resolve disputes. His control over water could also be extended to other substances that have a connection to water, like steam or ice, in a more efficient way than before. And his powers of persuasion, which could be influenced by Hera, might be used to calm angry sea storms or make sea monsters cooperate with him, which is an interesting combination of his Poseidon - given powers and Hera - influenced skills.
His powers would likely be much darker. He might have the ability to manipulate shadows like Nyx, using them to hide or even attack. And from Tartarus, he could have the power to cause earthquakes or open up chasms in the earth. He could also have a natural resistance to the harmful effects of the Underworld, such as the poisonous gases and the draining of energy that normal demigods experience.
His powers would likely be a blend of Greek and Norse elements. For example, he might still be able to control water like in his Greek demigod abilities, but also have some connection to ice or snow from the Norse side. Maybe he could freeze water in a way that's more related to Norse frost magic.
Well, if Percy was more powerful, he could act as a stronger mediator between Zeus and Poseidon. He might be able to force them to face their issues more directly. For example, he could use his increased power to create situations where they have to work together, like in the face of a new and extremely powerful enemy. This could lead to a begrudging respect between the two gods and a shift in their relationship from one of constant bickering to a more cooperative one, at least when Percy is around.