Son of the Black Sword by Larry Correia
This is the first book in his series "Saga of the Forgotten Warrior". Correia has created a fantasy world where boys from ruling houses are trained as warriors to uphold the law and where the casteless are not even considered human. The story revolves around one main fearless warrior, Ashok, who discovers a secret about his life that changes everything he thought was true. Full of descriptive battles, demons and wizards, with all of them vying for power, this is a book for those that liked "The Witcher" and " Game of Thrones".