Perhaps in the fanfiction, they reunite while on individual vacations in a small, idyllic town. At first, it's awkward, but then they start reminiscing about their old times. They decide to have a private jam session, just like the old days, which leads to discussions about a possible comeback.
It could be Harry Styles. Since he has had a very successful solo career, he might be the one who initiates the reunion, using his influence and popularity to bring the boys back together.
It could be a very emotional reunion. Thor might be initially angry at Loki for all his past misdeeds but then quickly soften as he realizes how much he has missed his brother. Loki, on the other hand, might be a bit guarded at first, still not fully trusting Thor's reaction. But eventually, they would embrace and start to rebuild their relationship.
Well, in the fanfiction, their reunion could lead to them teaming up. Maybe they decide to take on a powerful enemy together. They'd combine their skills, with Ace's fire powers and Sabo's fighting abilities, and create a formidable force. They'd also probably have some deep conversations about their past and how much they missed each other.
Their relationship could develop romantically. After the reunion, they might start to realize their feelings for each other more clearly. For example, they could share more private moments, like watching the sunset together while their Pokémon play nearby.
Well, in a fanfiction, their reunion could be in a completely new region. Ash has been invited to a special Pokémon event there and Serena, having heard about it, travels all the way just to see him again. When they reunite, Serena has become an even more confident and skilled Pokémon coordinator. Ash is so proud of her growth, and they decide to team up for a new adventure in this unfamiliar region.
They might have a very emotional moment. Sasuke could finally open up about his long journey and all the things he has been through. Sakura, on the other hand, would be so happy to see him again and might just break down in tears. They could share a long hug, a hug that they both have been waiting for for so long.
In a Draco and Hermione reunion fanfiction, they might initially be hesitant. Draco could be ashamed of his past actions during the wizarding war. Hermione, on the other hand, might be curious yet guarded. Maybe they meet in Diagon Alley by chance. Draco could be there to buy some rare potions ingredients for his new business venture. Hermione is browsing the new books at Flourish and Blotts. Their eyes meet, and there's a moment of shock. Draco, trying to be polite, nods. Hermione, after a brief hesitation, nods back. And that could be the start of a series of unexpected interactions.
It could shift the power dynamics. Their combined strength would make them a significant force. Enemies might be more cautious or new alliances could form.