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.
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.
A possible plot for a Merlin love potion fanfiction is that the love potion has a reverse effect. Instead of making someone fall in love, it makes them hate the person they previously loved. Merlin has to find a way to reverse this before it causes too much damage. Another plot could be that a magical creature gives Merlin the love potion recipe, but it comes with a price. Merlin has to complete a series of dangerous tasks in order to use it. And lastly, the love potion could be used to make an arranged marriage work. Merlin uses his magic to create a love potion to ensure the happiness of the couple, but he has to be careful not to be discovered.
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.
The love potion can initially create a false sense of love. For example, if Draco is under the influence of a love potion for Harry, he might act overly affectionate, which could make Harry uncomfortable at first. But it could also be a catalyst for them to start interacting more, which might lead to a real relationship later.
Sonic might be really confused if he is under the effect of the love potion. He's always been independent and suddenly having strong romantic feelings for Amy would be a big change. He might try to fight the feeling at first because it's so alien to him.
Sheen is very likely to be affected. He's impulsive and would probably be one of the first to come into contact with the love potion. His over - the - top personality would make his actions under the influence of the potion really exaggerated, like falling in love with the most random things. Carl could also be affected. He's a bit of a follower, so if Sheen gets affected, Carl might follow suit without realizing it. And of course, Cindy. Since she and Jimmy have that sort of love - hate relationship, if she gets affected by the love potion, it could lead to some really interesting and comical situations between them.
It could also complicate their relationship. If they find out it was a love potion that made them feel this way, they might question whether their feelings are real or just the result of the potion. Naruto, being a straightforward person, might struggle with this idea. He wants to believe that his feelings for Hinata are genuine, but the existence of the potion makes him doubt.
One idea could be that Hannibal, being the complex character he is, accidentally ingests a love potion. He initially tries to resist the effects as it goes against his controlled nature. But as the potion takes hold, he finds himself drawn to a character in an unexpected way, leading to a series of internal and external conflicts as he battles between his true self and the potion - induced feelings.
Well, he might initially be confused. Since it's a love potion, he could start having strong, uncharacteristic feelings for Dravo. Maybe he becomes overly affectionate towards Dravo, not really understanding why these new emotions are surging within him.