Papyrus might be initially shocked. He's used to Sans being more laid - back, so seeing him in a fight could be quite a surprise. His eyes would widen and he might gasp.
One great idea for a fanfiction could be a story where Underswap Sans and Underswap Papyrus go on an adventure in the Underground. Maybe they encounter a strange new monster that no one has ever seen before. They have to use their unique abilities to figure out how to deal with this new threat.
One characteristic is the strong focus on their brotherly relationship. Fanfics often show how Sans and Papyrus rely on each other, like in how Sans might be the more laid - back one while Papyrus is full of energy and enthusiasm, and they balance each other out. Another is the use of the unique Underground setting. It provides a backdrop for their adventures and interactions. For example, they might be dealing with other monsters while also strengthening their own bond.
Well, in 'underfell sans x papyrus fanfiction', their relationship is a key aspect. It can vary greatly depending on the author's interpretation. Some may focus on the loyalty between them, despite the cruel environment of Underfell. Others might explore how their personalities clash or complement each other. For example, Sans' cynicism in Underfell might contrast with Papyrus' more naive side, creating interesting storylines and character developments.
There's also 'Swap Brothers' Bond'. This fanfic delves deep into the brotherly bond between Sans and Papyrus in the Underswap setting. It shows their daily adventures and how they support each other. The author does a great job of capturing the essence of their swapped selves, and it's full of humorous and touching scenes.
A popular sans x papyrus fanfic is 'Shared Skies'. It has a really interesting plot where they face a new threat together in the Underground and their bond grows stronger as a result. 'Soulful Bonds' is also a good read. It dives deep into their emotional connection and how their personalities complement each other. 'Brotherly Love' is a simple yet effective fanfic that just showcases the pure love and care they have for one another.
A great idea could be a story about their daily adventures in the Underground. For example, they could be on a quest to find a rare ingredient for a new recipe Papyrus wants to try. This would focus on their brotherly bond and Papyrus's enthusiasm for cooking, while Sans tags along with his laid - back attitude.
A great Underswap Sans x Papyrus fanfiction might be the one that delves into their backstory. It could explore how their relationship developed from when they were younger. Maybe there was a time when they had a big fight but then learned to understand each other better. This kind of story can be really heartwarming as it shows their growth and the strength of their brotherly love.
A third common theme is self - discovery. Both Papyrus and Sans might learn new things about themselves as they interact with each other and face various situations. This can be really interesting as it shows their growth as characters. For instance, Papyrus might discover a new side of his personality when he has to protect Sans in a dangerous situation.
Common themes in 'underfell sans x papyrus fanfiction' include power dynamics. Since Underfell is a harsher world, there might be a shift in the power balance between Sans and Papyrus. Additionally, redemption can be a theme. Maybe one of them has made mistakes in this unforgiving world and is seeking redemption. Also, the theme of trust, as they need to trust each other to survive in such a difficult environment.