Hyakunen no Valkyrie

Once every hundred years, a phenomenon occurs in which a single man is given a "god sword" by the valkyrie. Seven years ago, one man received this power and ushered in a revolution in the northernmost country of Lorecia. Lorencia's prince, Nikolai, who lost everything in the revolution, encounters a new valkyrie. And thus fate begins to turn.

(Source: MU)