His powers could be enhanced in some aspects. In the past, the connection between mortals and the gods was stronger. Since Percy is a demigod, he might have a closer bond with Poseidon in an earlier time, which could boost his water manipulation skills. On the other hand, the different magical environment of the past could also bring new limitations. For instance, there could be ancient spells or curses that interfere with his ability to call upon water when he needs it.
His water - based powers might be affected in different ways. If he goes back to a time when the oceans were less polluted, the purity of the water could make his powers stronger. However, if he goes to a time when the gods were more in control of the elements, they might be able to limit his power. For example, Poseidon might have more say over how Percy can use water powers if they are in the same time period.
If Percy is thrown back in time, his powers could be enhanced. In the past, magic and the power of the gods were more prevalent. The very air might be charged with more divine energy. His ability to communicate with sea creatures could expand, as there could be species that are now extinct or have evolved in his own time. However, he might also face limitations. For example, if he goes back to a time when the gods were at war, some of his powers related to Poseidon might be restricted depending on his father's situation in that war.
His powers might not be affected at all. Percy's connection to water is more about his essence as a demigod rather than his physical form. So he could still control water, summon sea creatures, and heal himself with water just as well as before.
His water - controlling power would be a huge advantage. For example, during naval operations, he could manipulate the sea to create safe passages or disrupt enemy ships. Simple as that.
The balance in nature would be disrupted. Artemis is the goddess of the hunt, the moon, and nature. Her death could cause strange phenomena in the natural world, like animals going wild or the moon's cycle becoming erratic. This would not only affect the demigods but also mortals who depend on the stability of nature.
His relationship with his father Poseidon would be different. He might see a side of Poseidon that he never knew before, like when Poseidon was younger and less experienced. This could change how Percy views his father and their connection.
In such a fanfiction, Percy might use his knowledge of the future to change some key events in the past. For example, he could prevent some of the earlier disasters or conflicts in the Percy Jackson universe. Maybe he'd try to stop the first encounter with a certain monster in a different way to avoid the chaos it caused.
Bellatrix's personality could be softened in some ways. Going back in time, she might see things differently. For example, if she goes back to a time when the wizarding world was more peaceful, she could start to question her loyalty to Voldemort. However, she could also become more desperate. If she realizes that she has a chance to change things for the worse in the wizarding world, she might be more eager to carry out her dark plans, and her already - extreme personality could become even more so.
His powers could be more nature - based. For example, instead of just controlling water, he might be able to control all forms of liquid in nature, like sap or blood. His connection to the wild could also make him more attuned to the emotions of animals, allowing him to communicate with them more effectively.
Well, in a fanfiction where Percy is born in Greece, his powers would likely have a more 'Greek - flavoured' aspect. Since he's in the homeland of the Greek gods, his connection to water could be intertwined with the Greek concept of the four elements. So, his water powers might interact more with the other elements in a way that is more in line with Greek elemental theory. He might also be able to draw on the power of Greek water deities more directly, which could enhance his abilities and give him new ways to use his powers in battles and other situations.
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.