One possible plot could be that the Reynes return with a newfound power. Maybe they have allied with some mysterious group during their absence. They could come back to claim their old lands and seek revenge on those who wronged them in the past. Their return might also stir up the political situation in Westeros, causing new alliances and rivalries to form.
The main character could be a former servant of the Reynes who has been waiting for their return. This person has a deep loyalty to the family and has been gathering information and resources in their absence. There could also be a character from the Faith of the Seven who is either for or against the Reynes' return, depending on how he interprets the teachings in relation to the Reynes' past actions.
In a fanfiction about the return of dragons in 'Game of Thrones', one possibility could be that the dragons bring a new era of balance to Westeros. They could help in rebuilding the kingdoms that were ravaged by war. For example, Drogon could use his fire to clear the rubble in King's Landing and then help plant new crops with his heat, making the land fertile again. Their return might also force the remaining lords and ladies to put aside their petty squabbles and unite under a new banner, perhaps one that represents the power and majesty of the dragons.
Perhaps the house gardener is an undercover spy. He uses his role as a gardener to move around different houses undetected. He could be passing on information about the layout of the castles, including secret passages and store rooms, which could be crucial in a siege or an assassination attempt. All the while, he has to maintain his guise as a simple gardener who is only interested in tending to the plants.
One possible plot could be Merlin, with his magic, finding himself in the world of Game of Thrones. He might use his powers to try and influence the power struggles. For example, he could help Daenerys control her dragons better or assist Jon Snow in his fight against the White Walkers. Maybe he would be seen as a sorcerer from a far - off land and have to prove himself to the different factions in Westeros.
Well, it could be about Naruto characters in the world of Game of Thrones with godlike powers. Maybe Naruto has the power to control the dragons like Dany, and he uses his ninja skills to fight in the Westeros battles. For example, he could use his shadow clone jutsu to confuse his enemies during a siege.
It could be about a character finding solace and protection in the king's arms. Maybe a love story between a commoner and the king, defying the odds and social hierarchies in the brutal world of Game of Thrones.
Well, it could be about some traitors in the Game of Thrones world who are trying to escape from a powerful enemy. Maybe they are fleeing from a vengeful lord or a powerful magic user. They might have to use their wits and whatever resources they have to get away, like finding secret passages or forging alliances with unexpected groups.
In a 'Game of Thrones Epilogue Fanfiction', it could be about the adventures of the next generation. The children of the main characters might discover new threats or mysteries. For instance, they could find hidden secrets about the White Walkers that were not fully explored in the original series, leading to a new quest.
One possible plot could be that Hermione, with her intelligence and magical skills from the Harry Potter universe, is transported to the world of Game of Thrones. She meets Jamie there. Maybe she tries to use her knowledge to prevent some of the bloodshed in Westeros. She could team up with Jamie, who has his own complex history and skills with a sword. Together they might try to bring about a more peaceful solution among the warring houses.
It could be about the last dragon in Westeros rising to power. Maybe it forms a bond with a new character who tries to use its strength to claim the Iron Throne. This person might face many challenges from the remaining great houses who don't want a dragon - backed ruler.