The baby might be a key to a long - forgotten mystery. It could be related to an ancient pact between the gods. Percy finding the baby could be a sign that something big is about to happen in the world of the demigods. The baby's identity could be slowly revealed as Percy and his friends investigate. It could be a symbol of hope or a harbinger of doom, depending on the circumstances surrounding its appearance.
Well, in his new life as a baby, he might grow up with a different family. Maybe he won't face the same initial hardships. He could be raised in a more stable environment, which would change his whole perspective. His relationships with the gods might also start off on a different foot. Instead of the rushed and often dangerous encounters he had before, he could have a more gradual and perhaps less hostile introduction to the world of the divine.
It would be really interesting. Since he's reborn as a baby, he and Annabeth wouldn't have the same initial connection. Annabeth might first see him as just a cute baby, not the hero she knew. Their relationship would have to build from scratch. She might be more protective of him at first, like an older sister figure, and as he grows up, their relationship could develop into a romantic one in a much more gradual way compared to their previous life.
The theme of innocence is also prevalent. Baby Percy is depicted as this innocent being in a big, scary world. His reactions to things are pure and untainted, and the fanfictions often play on this contrast between his innocence and the dark and dangerous world of Greek mythology that he will eventually have to face.
The relationship could be shown as a curious one. Since Percy is a baby, he might not fully understand who Poseidon is, but there could be an instinctual bond. Poseidon, on the other hand, could be filled with a sense of wonder at this small version of his son, seeing all the potential in him. He might try to communicate with Percy in gentle, non - verbal ways, like sending small ripples of water to make Percy laugh.
Perhaps some of the minor gods who are tired of the traditional power structure in Olympus could be Percy's allies. They might see his rebirth as a son of Chaos as an opportunity to shake things up. Also, any being that has a connection to the concept of change or new beginnings could potentially side with Percy. This includes spirits of innovation or even some forgotten heroes who sense that Percy is the key to a new era in the world of demigods and gods.
One interesting storyline could be Percy as a baby showing early signs of his demigod powers. Maybe he can control water in his crib, like making the bath water swirl around him in a mini - whirlpool. Another could be the reactions of the gods when they discover this new baby demigod. They might be worried about his potential or already planning how to use him in their future schemes.
Perhaps the baby has some unique powers. Percy finding the baby could be the start of a whole new adventure. He could take the baby on a journey to find out more about its parents. Along the way, they might encounter old enemies of Percy's or new threats. The baby could also form a special bond with Percy, and as it grows, it could become an important part of the demigod world. Percy would have to teach the baby about the world of gods and monsters, and how to survive in it.
Family is also a big theme. Even though they are at a camp, the baby demigods form a sort of family unit with the other demigods. Some fanfictions explore how these relationships develop, whether it's a sister - like bond between two female demigods or a big - brother - like figure looking out for the little ones.
If Percy were a baby in fanfiction, the power dynamics at Camp Half - Blood would shift. Without Percy's combat skills and leadership, others would need to fill the void. The story might focus more on the characters' attempts to protect and care for baby Percy. And there could be new plotlines about finding a way to reverse his condition, which could involve seeking help from new or unexpected sources.