Creating My Own Army (on hold) Alpha, OP MC

[Current World: Naruto ]
this story is about a person who dies in AU of Earth where kingdoms still exist the MC being the youngest war general due to war with a stronger kingdom dies and is offered a job that entitles fighting monster and armies but comes with the benefits of going through and getting power if chosen to accept or simply go to heaven or get reincarnated in your world again. continue reading

this is not a harem for the simple reason that I can't make it happen I tried in my first fanfiction but never found a good way to introduce a reason for it and I have read many harem stories and despite not hating the harem idea as fiction but the reasons in the stories I read for it is simply ridiculous and just doesn't work for me like "he is so strong I need sisters" or "he is the last of his clan so he needs more wives"....etc. so this if I decide on a romance it will be a single pairing.
// Disclaimer: I don't own the world or the characters that my OC goes to only his character nor do I own the cover pic and if the owner wants it removed contact me