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 what would happen if Maleficent had a baby with a human. Maybe the baby would have a unique blend of magical and human traits, and the story could follow how the baby is accepted or rejected in both the human and magical worlds.
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.
One idea could be exploring the backstories of the minor characters in the House of Hades more deeply. For example, delving into the history of some of the shades that are often just in the background.
Well, you could have a plot where Persephone and Hades have an argument over her time split between the Underworld and the upper world. This could lead to her leaving for a while and Hades having to go through a series of trials to win her back. Another idea is that they discover a new part of the Underworld together that has been locked away for ages and it holds a great power. They must figure out what to do with this power without causing chaos in both their worlds.
One idea could be that Maleficent, intrigued by the magic in the wizarding world of Harry Potter, decides to visit Hogwarts. She could end up teaching a special class on dark magic defenses, which would put Harry and his friends in an interesting situation as they learn from a very different kind of magic user. Another plot could involve Maleficent getting involved in the fight against Voldemort, either as an ally or with her own motives that might not be entirely in line with the Order of the Phoenix. Maybe she wants to use the chaos to gain more power for herself in the wizarding world.
One idea could be a story where Maleficent tries to teach Aurora about the dark magic she possesses in a more positive way. Instead of seeing it as just evil, she shows Aurora how it can be used for protection and to understand the balance in nature.
You could write about how Hades and Persephone first met in a different way than the traditional myth. For instance, Persephone could be exploring the Underworld out of curiosity and Hades mistakes her for a lost soul at first. Then as they start to talk, they realize there's a special connection between them. This could lead to a whole new story of how their relationship developed from that unexpected encounter.
One idea could be Percy having to navigate the Underworld politics due to his relation to Hades. He might face challenges from other underworld creatures who don't trust him. Another could be Percy using his newfound powers as the son of Hades to fight against an ancient evil that threatens both the mortal and underworld realms. Or perhaps he has to deal with the stigma of being Hades' son in the demigod community and prove himself worthy.
Another plot could involve Percy's relationship with his father, Hades. Maybe Hades has some grand plan for Percy that he doesn't fully understand at first. Hades could be trying to use Percy to gain more power in the world of the gods, but Percy resists and has to fight against his father's wishes while also dealing with the internal conflict of not wanting to completely turn his back on his family.
One plot idea could be Mal struggling to fit into the Underworld society that Hades rules. Since she's from a different world in Descendants, adapting to the dark and often chaotic nature of the Underworld could be full of challenges and interesting character developments.