In a fanfic like this, Merlin might accidentally give Arthur a love potion. Arthur could then fall in love with the first person he sees, which could be hilarious or cause chaos. For example, if he falls for a random servant, it would disrupt the normal order of the court. And Merlin would have to find a way to reverse the potion's effects without getting into too much trouble himself.
Well, it could start with Merlin finding a love potion in some old wizard's lair. He might be curious about it and accidentally spill it near Arthur. Arthur, under the influence of the potion, might start acting really strange. He could become overly affectionate towards Merlin himself. This would be quite a shock to Merlin, and he'd struggle to keep Arthur's newfound 'love' a secret while trying to find an antidote.
The love potion could make Arthur see Merlin in a whole new light. He might suddenly be more trusting of Merlin's magic, which is usually a big issue between them. For Merlin, it could be a chance to get Arthur to listen to his ideas more easily.
In a Hermione potion accident fanfic, she might accidentally create a potion that causes strange transformations. For example, she could turn into an animal or have her appearance altered in a unique way. This could lead to all sorts of adventures as she tries to reverse the effects. Her friends, like Harry and Ron, would likely be involved in helping her figure out what went wrong and how to fix it.
Well, perhaps Merlin has made a big mistake in Arthur's eyes. Maybe he used magic in a way that was too obvious or endangered the kingdom, so Arthur, in his kingly way, sends Merlin to the stocks as punishment.
In fanfics about their friendship, their contrasting personalities play a huge role. Arthur is the proud and noble prince, while Merlin is the bumbling yet powerful servant. This contrast leads to some really interesting and humorous situations. They start to understand each other better over time. Merlin learns about Arthur's responsibilities as a future king, and Arthur begins to see Merlin's loyalty and the value of his unique abilities.
Maybe Captain America accidentally drinks a love potion and falls for a civilian. This could put the civilian in danger as his enemies might target her to get to him. So, he has to protect her while also trying to figure out how to reverse the effects of the potion.
In a Johnny Test love potion fanfiction, the love potion could be part of a science fair project. Johnny's intention was to create a potion that would make people like each other more in general. But when he tests it on himself, he falls in love with the concept of time travel (because he was thinking about it right before taking the potion). So he starts trying to build time - travel machines to be closer to what he loves, and his family has to stop him before he causes a time - related disaster.
A simple scenario could be that a love potion is slipped into Hannibal's drink at a social gathering. He then starts to have strong feelings for someone he previously only had a professional relationship with. This changes the dynamics between them completely, leading to awkward and intense situations as they both try to figure out what's going on.
Well, in the 'arthur meets a human fanfic', it could be that Arthur initially has some misunderstandings with the human. But as the story progresses, they start to understand each other better. The human could introduce Arthur to human culture, like different kinds of music or food. And Arthur could show the human some unique things from his own world. For example, if Arthur has some special abilities, he could use them to help the human in a difficult situation. Maybe they end up having a strong bond that crosses the boundaries between their different existences.
One possibility is that the truth potion gets misused. For example, an enemy of Harry and Hermione might get their hands on it and try to use it on them. But Hermione, being the brilliant witch she is, could find a way to turn the situation around. She might use her knowledge and quick thinking to make the enemy believe false information while under the influence of the potion. And this could be a crucial part in their fight against the dark forces.
Obviously Merlin himself could be affected. He's the one with the magic and might accidentally expose himself to the potion. Arthur is also a likely candidate. As the king, if he's affected by the love potion, it would have a huge impact on Camelot. Morgana could also be a character affected. If she were under the influence of a love potion, it could change her plans and her relationships with other characters. And Guinevere too, since she has important relationships in Camelot that could be altered by the potion.