Rogue: Planet Athion by Debbie Cassidy

Each Victory is another day I get to continue breathing. Each Victory is a reprieve from Death.
Ever since I was betrayed and taken from my home planet, ever since they pumped me with poison and abandoned me on this asteroid to fight or die, I’ve been surviving.
But I’m not alone.
There are others with me, alien to me, just as I am to them. Separated into Houses we fight as a team on the blood-soaked sands while the elite watch.
Each day is about survival until him.
An outsider, he brings death, but he might also be our salvation.
There can be no us and them. There can be no prejudice. There can only be the team, because together we are stronger.