Everyone called satan many names but the one name everybody feared was the name shadow monarch because he can resurrect his enemies as immortal shadow soldiers at his command but after the great war, they thought satan died while fighting the biblical god 500 years ago but little do they know he was on the earth and had a son and daughter named issei and akame(yes I mean akame from 'akame ga kill', and you will know what will happen next. I forget to say that some parts of the story are from the story "The son of the true satan" on fanfic.net if you want to read it here's the link. https://m.fanfiction.net/s/12368438/1/The-Son-of-The-True-Satan just copy and paste it.