The Condemned: Bloodforged Reckoning

In a world where martial power rules all, Gordon Stone loses all nine of his sons in the war against Nethra. Instead of being hailed as heroes, they are branded as cowards, and Gordon is condemned as a traitor who sold out his own people. Nine empty coffins are sent to shame him. Then, the system that arrived a century late finally awakens: kill to grow stronger. Carrying the coffins on his back, Gordon returns to war to clear his sons' names and protect mankind.