Well, to develop it, you could start with the idea of Naruto being born in a different realm where Zeus and Hera rule. Maybe there was some sort of prophecy that led to his birth. His abilities could be a mix of ninjutsu and divine powers. He might have the ability to control lightning like Zeus and also possess some form of protection magic from Hera. The fanfic could then follow his journey back to the Naruto universe and how he uses his new powers to protect his friends and the village.
One way this could work in the fanfic is through a time - space distortion. Imagine that a rip in the fabric of reality opened up between the world of Naruto and the realm of the Greek gods. Zeus and Hera, being curious or having some grand plan, sent a part of their essence through this rift. This essence then combined with elements in the Naruto world, resulting in Naruto being born as their son. This would also bring about all kinds of new powers and abilities for Naruto, as he would inherit some of the divine qualities of Zeus and Hera.
One plot could revolve around Naruto being sent back and forth between the ninja world and the realm of the Greek gods. As the son of Zeus and Hera, he has duties in the Greek god realm, like dealing with the power struggles among the gods. At the same time, he still has his ninja responsibilities in his own world. He has to use his combined skills and powers from both worlds to keep peace in both realms.
For the plot of this fanfic, it could start with Naruto having strange dreams about a powerful couple. These dreams lead him on a quest to discover his true identity. Once he realizes he is the son of Zeus and Hera, his life changes completely. He is now part of two worlds. In the shinobi world, his old enemies become even more wary of him, and some new allies emerge because of his new status. In the divine world, he has to learn the ways of the gods and deal with their complex relationships. There could be a main antagonist who wants to destroy the balance between the two worlds, and Naruto is the only one who can stop it. He uses his ninja skills combined with his divine powers to face this threat.
In this fanfiction, Naruto's appearance might be different. Since he is the son of two powerful gods, he could have a more majestic look. His eyes might glow like lightning or have a special color. His story could involve him trying to fit in with the normal ninjas while also coming to terms with his divine parentage. He might face discrimination from some who fear his power, but he overcomes it with his kind heart, just like in the original Naruto story.
Well, one way could be that Naruto inherits some of Zeus's powers like control over lightning, which he could then combine with his own chakra-based abilities. For example, he might be able to create super - powerful lightning - based jutsus that are far more destructive than his regular Rasengan. Another aspect could be the cultural clash. Naruto, coming from the Hidden Leaf Village in a ninja - based world, would have to deal with the very different world of Greek mythology where Zeus rules. He could be seen as an oddity, and this could lead to various adventures and conflicts as he tries to find his place in this new, strange world that is somehow related to his heritage.
The plot could revolve around Percy's relationship with his divine parents. Since Zeus and Hera have a complex relationship themselves, Percy might struggle with their expectations. Maybe he's caught in the middle of a power struggle between Zeus and Hera's different ideas of how he should use his powers. He could also be trying to unite the camps of different god - related demigods under his leadership as the son of two major gods.
I'm not sure about a specific 'Percy son of Zeus and Hera fanfic' that stands out above all others. However, you can try looking on fanfic platforms like Archive of Our Own. There, you can search for this specific type of fanfic and read the reviews to find a really good one. Usually, the ones with high ratings and a lot of bookmarks are worth checking out.
The Titans could be the main antagonists. Even though they were defeated before, they might see Percy as a threat because of his powerful parentage. They could try to stop him from fulfilling a prophecy or gaining more power. For example, Kronos might have some remaining influence and try to manipulate events to destroy Percy.
For Hera, you could develop her character by showing her softer side. In a lemon fanfiction, she might let down her guard more easily. Maybe she starts to communicate her true feelings to Zeus instead of always being angry. For Zeus, you can show his growth in understanding Hera better. He could start to respect her more and value her opinions.
If Naruto was the son of Zeus and Hera in a fanfic, he would likely have some form of lightning - based powers from Zeus. Zeus is often associated with lightning, so Naruto might be able to summon powerful bolts of electricity or even use lightning to enhance his speed and strength. From Hera, he could gain powers related to protection and leadership. Hera is a goddess who looks after marriage and family, so Naruto might have an innate ability to protect his friends and comrades like they were his family, and also possess strong leadership skills to guide them.