Well, one possible plot could be that Sans discovers a mysterious magic spell or artifact that gradually transforms him into a human. As he changes, he has to deal with new sensations like feeling pain and hunger in a more intense way. He also might struggle with how other characters in the Undertale world view him now that he's different.
It could be another monster who is jealous of Sans getting all this new - found attention as he turns into a human. This monster might try to stop the transformation process or make Sans' life difficult in his new human form.
Maybe in the fanfiction, there's a scientific experiment gone wrong. A human scientist was trying to find a way to bridge the gap between humans and monsters. Sans, being a curious skeleton, volunteered to be a part of the experiment. However, instead of just creating a connection, the experiment transforms Sans into a human. As a human, he experiences new emotions more intensely, like hunger and fatigue, which he didn't really have as a skeleton. He then uses his new human form to try and convince other humans that monsters are not to be feared.
It could be another monster who is jealous of Sans' new form. This monster might feel that Sans is getting special treatment or opportunities because he's now a human. So, this jealous monster tries to find a way to either turn Sans back into a skeleton against his will or make his human life miserable by causing trouble for him in the human world, like spreading false rumors about him.
No. The Undertale community is mainly about positive things like friendship and hope. Abuse of any character, especially in a fanfiction, goes against the values of the community.
The integrity of Sans in fanfiction might also be reflected in his honesty. He doesn't deceive others easily. He may face difficult situations where lying could seem like an easy way out, but he chooses to be truthful. This aspect of his character makes him reliable and trustworthy in the fan - created stories.
One aspect to consider in undertale chara x sans fanfiction is the exploration of their unique personalities. Chara is often depicted as a complex and somewhat mysterious character, while Sans has his laid - back yet deeply knowing side. Their interactions can range from tense to surprisingly harmonious. In some fanfictions, they might be brought together by a common goal, like saving the Underground in an alternative scenario.
The fan base loves these characters so much that seeing them interact in new and unexpected ways is always a treat. The relationship between them can be explored in so many different ways, from friendship to rivalry. And the unique art styles and interpretations that often come with these fanfictions add to the overall appeal. There are also some really emotional stories that can be told about them finding common ground or learning from each other, which really tugs at the heartstrings of the readers.
One common theme is friendship. The OC often forms a strong bond with Sans, going through various adventures together. Another theme is self - discovery. The OC might be on a journey to find out who they are in the context of the Undertale world.