Bristlefrost wasn't my favorite character out of this arc's trio, Rootspring was, but her death was very surprising. I don't think any other cat has died in their arc before. (I like this, but I'm pretty sure Ivypool was there as well. I was laughing when Ashfur died- he fricken murdered Graystripe)
(Ivypool? Pretty sure it was Violetshine.)