Novel Tale, a changeling living in Canterlot as a writer, has his peaceful life shattered when changelings from another hive attack, revealing the existence of changelings to all of ponykind. And his last book had a changeling character in it...
Zevan was a loyal changeling and did his queen's bidding, although he questioned why she had broken the peace. After being badly injured though, he had to reconsider his future, and a unicorn mare with a broken horn was a surprising part of it.