Wolf Spirit Keito, is an another version of Abriter Keitoku, Keitoku being the younger version of them. Keito seeks to reform the world, even if it means war. 
After the war, a princess, named Nyxeria Luiselle, from another world called “The Erebrium Plane of Darkness” could summon him as one of the war spirits, but although Keito didn’t know that he was one of the war spirits.
Nyxeria Luiselle and Keito would get married later on and have two kids.