Poseidon's power over the sea and Demeter's power over the land could create some interesting interactions. For example, Poseidon could bring rain from the sea to water Demeter's crops. Demeter could, in return, make the land near the coast more fertile, which would attract more sea life for Poseidon. In a love story, they could use their powers to create beautiful and unique places. Like a lagoon surrounded by the most fertile land, filled with fish and beautiful plants.
A plot could involve a prophecy that the union of Poseidon and Demeter would bring either great prosperity or great disaster. This prophecy sets the stage for their relationship. They start to secretly meet and fall in love. Poseidon might use his powers to create special underwater gardens for Demeter, and Demeter could make the lands near the sea more fertile in return. But as their love deepens, the other gods start to notice and some, like Zeus, might be worried about the implications of the prophecy. So they try to keep their relationship hidden while also trying to figure out how to deal with the prophecy.
In Percy Jackson fanfiction, the idea of Percy having a relationship with Demeter is quite an interesting concept. Demeter is the goddess of the harvest. A possible scenario could be that their love is based on Percy's respect for nature which Demeter represents. Maybe Percy helps Demeter in a quest related to protecting the harvest and in the process, they develop feelings for each other.
A sense of mystery and discovery is often a theme as well. Their relationship is not a common one in the original lore, so fanfiction writers like to create a sense of mystery around how they meet, what draws them together, and what the future holds for them. It makes for an exciting read as the readers get to discover these aspects along with the characters.
Another theme is the power dynamics. Hades has power over the underworld and Demeter over the harvest. In fanfictions, this often leads to interesting scenarios where they either use their powers for each other or face conflicts because of them. For example, Demeter's control over the growth of plants might be affected by her relationship with Hades.
One interesting story could be where Demeter and Hades meet secretly in the Underworld. Demeter, initially hesitant due to her association with the living world and nature, is drawn to Hades' mysterious and powerful nature. They start to share stories of their different realms, and over time, a deep bond forms.
Often, it's portrayed as a somewhat unexpected pairing. Demeter, with her stern and earth - motherly nature, might initially be aloof to Percy. But as the story unfolds, she could see his good heart. For example, Percy might show kindness to the plants and animals under Demeter's care, and that could start to change her view of him.
One great 'Hades and Demeter love fanfiction' is 'Love in the Underworld' which explores their relationship in a very unique way. It delves into how their different realms might interact with their love.
One interesting fanfiction could be where Athena and Poseidon are forced to work together on a project for the gods. In this story, their initial animosity slowly turns into an unexpected love. It might explore how their different personalities, Athena's wisdom and Poseidon's power, clash and then complement each other as they fall in love.