The Strongest Magician in the Demon Lord's Army Was a Human

Ike, a human, was trained in magic by Romberg, a powerful demon warlock, and rose quickly through the ranks of the Demon Lord's army. He led his brigade to multiple victories against humans, but kept his true identity hidden, knowing the consequences of being discovered. Ike's goal was to find a way for humans and demons to coexist peacefully, ending the long-standing war.