Nephilim of the End

(y/n) is a half angel that was first to be turned by the first progenitor. He was born in the land now called Spain and lived for over 1600 years. He is the true leader of the progenitor council. He had a family before but lost them. He may still have emotions and some kindness left inside him with care for some of earth's humanity. He heard about the Japanese Demon Imperial Army at Japan. He decided to finally intervene. He despises demons more than any human. No one and not even the first progenitor knows his secret of being a half angel and paladin the whole time. What will he do in Japan? How would others feel about he truly is?