make him to get Sacred Gear. my suggest is [Mastema], Teigu in Akame Ga Kill!. having some power is still acceptable if MC will involve in canon's conflict. Also, normal sacred gear is still common in series's character. my suggest harem is Asia, Irina, Xenovia. And they'll still human, or maybe all of them become angel later. [Asia and Xenovia join in Heaven faction like Irina]
Netapel
Liked by 3 people
LIKEnah having Irina , Asia and xenovia is too cliche and from the way the story is going I dont think Asia , xenovia and Irina are joining the harem , i can guess the potential harem members based on how the story is going the way i think it , the harem is likely going to consist of , yokai , important females from other pantheons , ruruko and maybe aika