In the first book we all know Brakentail was kinda a bully. But he's really just misunderstood. I mean, he was mean to Star and gave away info because he was trying to protect Morningleaf. And in Landfall (btw if you haven't read Landfall yet don't read this because it's a little bit of a spoiler) we learn that he gave information, but Rockwing was forcing it out of him a little. We all know he was protected and Echofrost was beat up and Brakentail tried to help her by bargaining with Rockwing! Even though it didn't work, it's the thought that counts. And he eventually accepts Star and swears to protect him. So he's really misunderstood. Even though he did a lot of bad things in the past, he was just trying to help. He also repents in the end. So he is very misunderstood, very very misunderstood.