Disclaimer: This story is my own personal headcanon of Underfell, which is A COMMUNITY MADE ALTERNATE UNIVERSE. There is no "100% accurate" version of Underfell since it does not belong to one individual, unlike some Alternate Universes like Underverse, ReaperTale, Handplates, GasterTale, OuterTale, etc.
Fighting is normal and encouraged, everyone is edgy, but killing for fun isn't okay in the monster community and neither is torture/rape/kidnapping. Monsters are tsundere punks/emos/goths/alternatives who just wanna listen to their rock music and get matching tattoos with their besties.
Oh, and the reader isn't perfect.
But hey, maybe give this story a chance. I put a lot of backbone into it. :)