Shield of the Waves (Highschool DxD x Male Reader)

(Y/N) (L/N) is a strange person, one who always strives to help just about anyone. Yet he always seeks a master for some reason, some say he was a loyal samurai in his past life, others say he's just a dog. There is nothing special about (Y/N) other than his talent, but he is fundamentally human. So why doesn't he des...