Arc Rise Fantasia

L'Arc Bright Lagoon is a legionnaire working for the Meridian Empire, whose simple life is turned upside down when, on a mission gone awry, he has a fateful encounter with Ryfia, a strange girl who calls herself the Imaginal Diva. It doesn't take long before L'Arc is discovered to be the Child of Eesa, the one destined to present a Law to Eesa and bring prosperity and guidance to the world. (TVTropes