Madan no Ou to Vanadis

Tigrevurmud Vorn, the young lord of a remote region far from the kingdom's center, is commanded by the king to go fight the war against a neighboring country. The leader of the enemy is Eleonora Viltaria, one of the seven Vanadis given supernatural arms from a dragon.
The moment when an archer boy and the silver-haired beautiful war maiden meet, it is the beginning for the legend of a hero that will be told for generations to come.

(Source: Crunchyroll)