They drop way more than just a defiant breast plate, guys.
Today one dropped a Honey-Covered Journal, which is for the Bixie Evolution Quest. That's the quest where you gather all the pages of bixie evolution and combine them to get a decent Range Slot item called Tome of Bixie Evolution. My guess is it's pretty rare, because I killed about a hundred of them and only one has dropped so far. The Honey-Covered Journal, I mean...