The Blood Prince by Marie Blanchet

Until two years ago, Rainbow was ruled by dragumens. Now, there’s a human Empress on the throne, and she rules with an iron fist. Breaking promises after promises, she controls the people with lies, taxes, and murder. Everywhere in the land, rebellion is brewing.

Gangav, the fallen dragumen prince who wants nothing more than revenge, rallies humans and dragumens to his cause. Sasha, his best friend and fiercest supporter, is eager to help him and is spoiling for a fight. Alexander on the other hand never wanted to be a part of it, but finds himself with no other choice when tragedy strikes home, bringing the cruelty of the empress to his doorstep. When news of a spy amongst their ranks turns everything on its head and the sudden outbreak of a new illness threatens the safety of the rebels, the three of them must find a way to relocate their camp before they are discovered, or the rebellion may very well end before it even begins.