Talk:Neutral Route/@comment-27524165-20160102035414/@comment-2234-20160115182135

That's not "Betrayed Undyne". That happens if you befriend Undyne, THEN kill any monster (but not Mettaton) afterward.

You cannot befriend Undyne if you killed anyone before encountering her. If you kill Mettaton after that, she'll become extremely depressed (because Mettaton's death leads to Alphys' suicide). If you kill any other monster after befriending Undyne, she swears vengeance upon you, and Papyrus tells you that you shouldn't ever return.