A fanfic could explore a scenario where Issei gets lost in a different dimension and Calypso is the only one who can guide him back. Along the way, they learn about each other's pasts and a deep connection forms between them. This could involve some action scenes as they battle strange creatures in that dimension.
Perhaps a story set in a post - apocalyptic world. Issei and Calypso are part of different survivor groups. They initially clash but then realize they need to work together. Their relationship evolves from distrust to love as they strive to rebuild the world.
You can try some popular fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfics from various fandoms, so there's a good chance you'll find some issei x calypso fanfic there.
One idea could be a story where Issei and Irina have to team up to face a new, powerful enemy that threatens their world. They start off as friends but gradually realize their deeper feelings for each other during the course of the adventure.
One popular 'issei x sona fanfic' could be 'A Chance Encounter'. It beautifully weaves a story of how Issei and Sona meet in an unexpected situation and how their relationship develops from there. Their interactions are full of charm and the plot often has interesting twists.
A plot could be where Calypso is somehow drawn into Naruto's world. Maybe a powerful jutsu gone wrong creates a portal. Calypso, being a powerful figure, is initially confused but quickly adapts. She and Naruto meet and at first are at odds as they misunderstand each other's motives. But as they get to know one another, they realize they can help each other. Calypso could use her magic to assist Naruto in a difficult battle against a new and dangerous enemy in the ninja world, and Naruto could offer his protection and loyalty to Calypso in return.
One great 'leo x calypso fanfic' is 'The Adventures of Leo and Calypso'. It beautifully portrays their relationship development. Another interesting one could be 'Leo and Calypso: A New Beginning' which focuses on how they start a new life together after their initial encounter.
A fanfic could explore the relationship between Percy, Calypso and the symbol of the lemon. Maybe the lemon is a rare fruit on Calypso's island and Percy has to go on a quest to find more lemons for a ritual. During this quest, they face various challenges together and their relationship deepens.
I'm not sure specifically which 'leo x calypso lemon fanfic' is the best. You could try searching on some popular fanfic platforms like Archive of Our Own. There might be some interesting ones there.
One plot idea could be that Issei and Yasaka meet by chance in a magical forest. They initially have a misunderstanding but as they spend time together, they start to see the good in each other. Another could be a story where they team up to fight a common enemy and during the battles, their relationship deepens. Or perhaps a plot where Issei accidentally enters Yasaka's territory and has to prove his harmlessness, leading to an unexpected friendship and more.
One common theme is adventure. Since both Leo and Calypso have had eventful lives, fanfics often put them in new and exciting adventures together. Another theme is love and its challenges. Their relationship is not always smooth, and fanfics explore how they overcome obstacles in their love.
Well, perhaps in the fanfic, the curse is not what it seems. It could be a ruse by an even more powerful entity. Percy, with his wits and the help of his friends, discovers this truth. He then has to figure out how to expose the real culprit and free Calypso. It might involve delving into some long - forgotten prophecies or seeking help from unlikely allies.