Sometimes, slipping through a hole in the world and ending up a servant to powerful fae is a terrible culture shock. A realm where people are imprisoned for killed for open contempt? Life at the whims of a vain, powerful entity who shapes the world to reflect their image?

Luckily!!??!? It doesn't have to be a sudden shock! There's options for that.

For this Papyrus, the human regularly resorted to killing, whenever they felt too endangered. Many of the more powerful monsters were slain: Toriel for trying to trap them, Undyne for her clear killing intent, Asgore for his openly merciless fight. But Papyrus plainly didn't want to kill them... And Mettaton likewise lucked out: the robot's fight was late enough in the journey that the human was more resistant to hurt, Alphys' ongoing "support" of the human further bolstered their morale, and - mainly - his preoccupation with fame and performance rather reminded them of the skeleton, and convinced them to wait him out. Though he would be dragged away injured and unconscious, Alphys would rebuild him, and Mettaton would rise to take the throne in the wake of the human's destructive passage.

Alas, Papyrus would never be certain whether the human killed Undyne, or if she too was merely injured and unconscious - or perhaps embarrassed and in hiding - when she disappeared. But he knew that other people who openly disliked the celebrity-turned-ruler tended to disappear, amidst rumors of dust, and feared the possibilities... Though that didn't stop Papyrus from working for his favorite celebrity, living the be-suited and be-shadesed life as an agent and seeing to matters of PR and Mettaton's good humor.

No, in some ways, it doesn't have to be a sudden culture shock at all. And now, in a world where telling stories for favors is really a giving away of memories, sooner or later someone with no willingness to kill may find himself becoming a very, very different skeleton.