Kaiten
Kaiten was a hero of the Great War who wielded an immortal-forged bastard sword known as Peace. He commanded GA troops in several campaigns. Eventually he married Nina and became King of Winlan, and he and his country were some of the most fervent participants in the Great War. However he vanished in the postwar unrest in that country and it was soon annexed by the Tasnica Republic.
He is not to be confused with the writer responsible for this character, Kaitenn.