Parona is a place for heroes. If you battle a monster and defeat it, you will receive valuable items. Otherwise, you'll die.
Lyrus is a semblance who gained conscious of being one. He became Cole's champion, and released all five monsters which ultimately led to many deaths, including Durny's. The reason was because Lyrus promised to protect Cole, but not everyone else.
It is stated that they could not ask the right questions and this occurred.