Definitely his sisters. They are constantly inventing things in the show, so in the fanfiction about Johnny getting a disease, they would be at the forefront of trying to find a cure. Another character could be his dad. He might be the one to comfort Johnny when he's feeling down because of the disease. And of course, Dukey would be there to provide some comical relief during the tough times.
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.
Besides Johnny, his sisters Susan and Mary would play major roles. They could use their scientific skills to research the disease and come up with possible cures. Then there's Dukey, who would be Johnny's constant companion during his illness. There might also be some of Johnny's school friends who could either be supportive or, in some cases, be a bit afraid of catching the disease from him.
His best friend. This person might be by his side throughout his illness, bringing him comfort, and trying to keep his spirits up. They could also be the one who helps Johnny find the best doctors or alternative treatments.
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.
Sodapop might be there too. He could be the one who tries to comfort Johnny after he gets beat up. Sodapop has a kind heart, and he would likely be very sympathetic towards Johnny's situation and try to make things better between the two warring parties.
Maybe it could be about Johnny's struggle with the disease, how he copes with the symptoms, and his journey to find a cure.
One common theme is identity. Johnny has to figure out who he is now as a girl. Another theme is family reactions. His family has to deal with this new version of Johnny, and it often leads to comical or heartwarming moments. For example, in some fanfics, his dad is completely clueless at first.
Some dedicated cartoon fanfiction forums might also be a good place to search. These often have a community of fans who write and share their Johnny Test and Buttercup fanfiction. Check out places where fans of the shows gather to discuss and exchange their creative works.
The story begins when a strange portal opens in Konoha. Out of it steps Johnny Test. Naruto is immediately curious. Johnny explains that he was working on a new invention and it accidentally opened a portal to this strange place. Naruto decides to show Johnny around Konoha. Johnny is amazed by the ninja academy and the training grounds. Meanwhile, some rogue ninjas from another village see Johnny as an easy target. But they soon realize their mistake when Naruto steps in. Naruto uses his ninjutsu to fend them off. Johnny, feeling useless, decides to use his brain. He quickly comes up with a plan using some of the materials he has in his backpack. He creates a device that disrupts the ninjas' chakra flow. With their combined efforts, they defeat the rogues. In the end, Naruto and Johnny exchange gifts. Naruto gives Johnny a kunai as a memento and Johnny gives Naruto a mini - gadget that can detect hidden enemies. Johnny then returns to his own world through the portal.
In fanfiction, the concept of female growth hormone in relation to Johnny Test could be used in various ways. It might be part of a science - themed story where a female character accidentally takes a growth hormone and Johnny Test has to help deal with the consequences, like her growing out of control and causing chaos in the town.
They could be part of a group of humans in a post - vampire - apocalypse world in fanfiction. Johnny's recklessness would constantly put the group in danger, but also sometimes lead to unexpected solutions. Mary would be the one to keep the group organized and come up with long - term plans. For example, she could figure out how to use the vampires' weaknesses, like sunlight or garlic, to their advantage and build a safe haven for the group.
One idea could be that Johnny Test and Bling Bling Boy are forced to team up in a science fair. They initially bicker but then realize they can combine their skills. Johnny's wild experiments and Bling Bling Boy's high - tech gadgets could create an amazing project.