One possible plot could be that Tails is captured by an evil scientist. The scientist then roboticizes him against his will. Tails has to struggle to keep his original self and memories while being forced to do the scientist's bidding. Eventually, he might break free from the robotic control through the power of friendship with Sonic and the others.
Well, perhaps in the 'tails gets roboticized' fanfiction, there is an accident in Tails' workshop. Some sort of malfunctioning technology starts to roboticize him bit by bit. As he becomes more robotic, he starts to view the world in a different way. His friends are horrified and try to reverse the process. Sonic might go on a quest to find the one thing that can save Tails, like a special chaos emerald or a rare component.
A rogue robotic entity could be the main antagonist. This entity has the ability to roboticize other beings and views Tails as a prime target. It wants to use Tails' body as a vessel to spread its robotic influence further, so it sets out to roboticize him and then use him as a tool for its own dark purposes.
One possible plot could be that Sally is roboticized against her will. She then has to struggle to retain her humanity while dealing with the new abilities and limitations of her robotic form. Maybe she tries to find a way to reverse the process.
Well, in this 'sonic gets roboticized fanfiction', it might explore the idea of Sonic's identity when he becomes robotic. It could show how his friends react to this new form. For example, Tails might be shocked at first but then try to find a way to reverse the roboticization. And Sonic himself could be struggling with feeling less 'alive' in his robotic state, all while facing new enemies or challenges that are related to his new robotic nature.
In addition to Sally, there could be other robotic characters in the fanfiction. Maybe there is a group of robots that Sally meets after being roboticized. They could either be friendly and help her understand her new state, or be hostile and see her as an outsider. And of course, her family members could also be characters, dealing with the changes in Sally.
Fans of Sonic who have a creative streak and an interest in exploring different scenarios for the character might write it. They could be young writers who are really into the Sonic universe and want to put their own spin on things.
One possible plotline could be Sonic struggling to come to terms with his new robotic parts. He might face challenges in his speed or his usual acrobatic abilities and have to relearn how to move and fight. For example, his robotic parts could malfunction at crucial moments.
Sorry, I don't have a specific 'sonic gets partially roboticized fanfiction' to recommend directly. But you can try searching on some popular fanfiction websites like Archive of Our Own or FanFiction.net.
In such a fanfiction, the plot might start with some ancient and dark jutsu that backfires on Naruto. As a result, the Nine - Tails gets pregnant. Naruto would be in a state of shock and confusion. He might seek help from the sages or other powerful ninja. Along the way, there could be those who want to use this situation for their own gain, while Naruto is trying to find a way to reverse the situation or accept it in a way that doesn't disrupt the balance of the ninja world.
Well, when Sonic gets roboticized in the comic, he has to adapt to his new mechanical state and battle against the forces that caused this change. There are lots of action-packed scenes and unexpected plot twists.
In such a fanfiction, Tails might be kidnapped by an old enemy like Dr. Eggman. His friends, like Sonic, would then start a rescue mission. They would search all over the place, from the Green Hill Zone to Eggman's secret bases.