One great fanfiction idea could be a story where Zeus, Poseidon and Hades have to team up to face a common threat that is even more powerful than them. Maybe a primordial being awakens and they must put aside their differences. In this story, Percy could be the mediator between them, using his unique position as the son of Poseidon to try and keep the peace among the three powerful gods.
There could be a fanfiction where Zeus, Poseidon and Hades are forced to attend a sort of 'godly therapy' session because their constant feuding is causing chaos in the mortal world. Percy, being the hero he is, is tasked with making sure they don't kill each other during the session. This would lead to some really interesting and humorous interactions as the three proud gods are made to confront their issues.
A fanfiction could explore the idea of Zeus, Poseidon and Hades in their youth. Before all the power struggles and enmity. They could be shown as friends, exploring the world and learning about their powers. And then something happens that starts to drive a wedge between them. Percy might discover an ancient relic that shows him these memories, and he uses this knowledge to try and mend their broken relationships in the present day.
A fanfiction could be about a competition among Zeus, Poseidon and Hades, and Percy has to be the judge. The competition could be something like who can best help a small, struggling mortal town without using their full power. This would show a different side of the gods and also test Percy's ability to be fair and objective.
One idea could be Percy having to mediate between Zeus and Hades during a major feud. Since he's the son of both in this fanfiction, he has a unique connection to them. He could use his powers and his knowledge of both of their domains to try and broker peace.
Yes, I recommend "The Dragon and the Swordsman and the Magician". Zeus, Poseidon, and Hades are all characters in this novel. At the same time, it was also a fantasy sword and magic novel. I hope you like this fairy's recommendation. Muah ~😗
Perhaps in the fanfiction, there could be a prophecy that involves Percy, Zeus and Poseidon. The prophecy states that only when the three of them perform a certain ritual together can they prevent a great disaster. But the ritual requires them to put aside their differences and trust each other completely. Percy has to convince the two powerful gods to participate.
In a fanfiction, Percy as the son of Zeus and Hades could have a very conflicted personality. He would be torn between the light and airy nature of Zeus's domain and the dark and brooding nature of Hades's. This internal struggle could be a major part of his character arc, as he tries to find a balance between the two aspects of his heritage.
One possible plot could be Percy struggling with the duality of his parentage. He might face discrimination from both the children of Hades and Poseidon. For example, the children of Poseidon could see him as a threat because of his connection to Hades, and vice versa. He could then go on a journey to prove that his dual heritage doesn't define him, but rather gives him unique powers to protect the world of the gods and mortals.
A powerful Titan who sees Percy as a threat to his plans. Since Percy has the power of Zeus and Poseidon, he could potentially stop any chaos the Titan wants to create. The Titan might try to turn Percy's friends against him or find a way to strip him of his powers.
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.
One interesting fanfiction could be about Percy Jackson's adventures that are more closely tied to his relation as Zeus's grandson. Maybe he discovers some hidden powers that are passed down only through the Zeus lineage. He could face challenges where his Zeus - related powers are both a blessing and a curse, like when he has to control excessive lightning powers during a battle with a powerful monster.
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.