Ashlords (Ashlords #1) by Scott Reintgen

Every year since the Ashlords were gifted phoenix horses by their gods, they've raced them. First into battle, then on great hunts, and finally for the pure sport of seeing who rode the fastest. Centuries of blood and fire carved their competition into a more modern spectacle: The Races.

Over the course of a multi-day event, elite riders from clashing cultures vie to be crowned champion. But the modern version of the sport requires more than good riding. Competitors must be skilled at creating and controlling phoenix horses made of ash and alchemy, which are summoned back to life each sunrise with uniquely crafted powers to cover impossible distances and challenges before bursting into flames at sunset. But good alchemy only matters if a rider knows how to defend their phoenix horse at night. Murder is outlawed, but breaking bones and poisoning ashes? That's all legal and encouraged.

In this year's Races, eleven riders will compete, but three of them have more to lose than the rest--a champion's daughter, a scholarship entrant, and a revolutionary's son. Who will attain their own dream of glory? Or will they all flame out in defeat?