"Monsters are people made of magic!" Frisk has instantly perked up. They can extol monsters all day. "They're really good and nice. Much better than humans."

Or so Frisk thought. The Underground has changed in disturbing ways since their death. But they're still better.

At the pathetic comment, Frisk's face closes off into an unreadable flatline. "S'nothing that can't be killed," they say, largely emotionless in tone except for a faint edge of a gentle reminder. Boy howdy have they learned that. Everything can kill or be killed.