Well, it could be about Will going on an adventure in the Underworld and meeting Hades by accident. Maybe he's there to rescue someone or he got lost. And then they have an interesting conversation where Hades reveals some secrets about the Underworld.
In this fanfiction, perhaps Will is a hero who has to face Hades as an adversary at first. But as the story progresses, they find out that they have common goals. For example, they both want to stop a greater evil that threatens both the mortal world and the Underworld. So they team up, and during this process, their relationship changes from hostility to mutual respect.
Their first encounter could be really intense. Hades might be sitting on his throne, all imposing, and Will would be a bit scared but also curious. Hades could use his powers to make the area around him seem even more menacing, like making the flames around his throne burn brighter.
One idea could be that the OC, as the son of Hades, struggles with the stigma associated with his father's realm. He could be trying to prove that he's not all about death and darkness. For example, he might use his powers to help the living in secret, like saving people from disasters that are on the verge of happening.
One possible plot could be that Persephone and Hades are overjoyed at the prospect of having a child. They start preparing a special realm within the Underworld for the baby. Hades might use his powers to create the most beautiful and safe nursery, while Persephone uses her connection to nature to fill it with gentle, glowing plants that can survive in the Underworld.
Well, it could be about Naruto having powers related to Hades on top of his ninja skills. Maybe he can control the dead or has some sort of underworld - like abilities that he uses in battles against the Akatsuki. He might also have to deal with the stigma of being the son of Hades in a world that doesn't understand such a thing.
Well, it could focus on the political implications. In Greek mythology, the gods often have power struggles. Their marriage could be a strategic move. Poseidon and Hades might join forces to gain more influence among the other gods. Maybe Zeus would be threatened by their union. This could lead to a series of events where they have to prove their loyalty to each other and their new combined rule while facing opposition from Zeus and his allies.
Well, perhaps the plot could involve Percy being given some special powers or protection by Hades. Maybe he's in a dangerous situation and Hades' blessing helps him survive or gain an advantage over his enemies.
Maybe Percy discovers that there is a conspiracy within the Underworld to overthrow Hades. As the champion, he has to uncover the truth and stop the plot. Along the way, he meets old enemies who now see him as an ally of Hades and try to take advantage of the situation.
The plot could start with Naruto being cursed by a powerful and evil entity. This curse slowly drains his life force and chakra. Hades senses this imbalance in the fabric of the universe. Since Naruto has a special energy that even affects the afterlife realm, Hades decides to save him. Hades brings Naruto to the underworld, where he uses his own unique magic to remove the curse. While in the underworld, Naruto discovers a new form of chakra that is linked to the souls of the dead. He then returns to the shinobi world, stronger than ever, and uses this new power to protect his village and friends.
One plot idea could be that Hades and Maleficent team up to take over the magical realms. They combine their dark powers and start by causing chaos in the fairy kingdoms. Another could be a love story where they initially clash but then find common ground and fall in love, changing their evil ways for each other. Maybe they could also form an alliance to fight a greater evil that threatens both their domains.
One idea could be exploring Persephone's adjustment to the Underworld. For example, she could start a garden in the gloomy realm using her powers over plants, which not only changes the look of the Underworld but also the attitude of its inhabitants. Another plot could be Hades trying to court Persephone in a more modern way, like taking her on a tour of different parts of the Underworld that are beautiful in their own dark way.