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.
In a love potion fanfiction, perhaps the love potion gets mixed up in the school cafeteria. Johnny Test is affected and he falls in love with his worst enemy at school. This leads to a series of comical situations where he tries to be nice to this person, while his friends are trying to snap him out of it and find a way to reverse the effects.
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.
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.
A possible plot for a Johnny Test love story is that Johnny falls in love with a girl who loves animals as much as he does. They both volunteer at the local animal shelter. Johnny is always trying to impress her with his ability to train the most difficult animals. However, a jealous rival tries to come between them by causing trouble at the shelter. Johnny has to prove his love and loyalty to the girl by solving the problems and showing that he truly cares about her and the animals.
One possibility is that Harry would suddenly become infatuated with Cho. He might start following her around, giving her gifts, and acting completely out of character. This would be a shock to his friends and cause a stir at Hogwarts.
The plot could be that Johnny falls in love with a girl who is a bit of a mystery. She shows up in town suddenly and has some strange powers. Johnny tries to figure out her powers while also trying to win her heart. He uses his inventions to impress her, like creating a time - traveling device to take her to see historical events. Along the way, they face some challenges, like an evil scientist who wants to use the girl's powers for bad. But in the end, their love prevails.
Well, perhaps there's a scientific experiment in Johnny's world that goes wrong. It creates a portal that sucks Naruto into Johnny's universe. Johnny's sisters think Naruto is some kind of alien at first. Naruto tries to find a way back home but gets involved in Johnny's adventures. They discover that an evil scientist in Johnny's world has plans to use ninja powers for his own evil deeds. So Naruto and Johnny, along with Dukey, have to stop him. They face many challenges along the way, like getting past security systems in the evil scientist's lair using Naruto's stealth skills and Johnny's hacking gadgets.
In the fanfiction, perhaps Johnny gets a disease that affects his superpowers. He used to be able to do all these amazing things, but now he can't. His dog Dukey might be by his side the whole time, trying to cheer him up. The disease could be something that was created by one of his enemies, and now he has to race against time to find a cure before it's too late.
In the fanfiction, Hermione might face a lot of internal conflict. The lust potion could make her have unexpected feelings towards someone. Maybe she'll struggle to resist the effects of the potion and try to maintain her self - control. It could also lead to some interesting interactions with other characters as they notice her changed behavior.
His sisters, Susan and Mary, would likely be main characters. They are smart and would surely try to help Johnny. Also, Dukey, Johnny's dog, would be important as he is always with Johnny through thick and thin.