Ingvild Leviathan
Half devil half human
Rank supreme class devil
Wielder of the New Longinus class sacred gear
Nereid Kyrie

Lucina
Half Human Half God
Rank lord class Goddess
Demi god Daughter of Poseidon
(Imagine her with little bigger Breast)

Sena
Rank lord class goddess
God Daughter of Zeus

Yumina (Fem Gilgamesh)
Rank Lord class goddess
Demigod

Yukina Himeragi
Fallen Angel
Rank Carde
6 pairs of wings
Wielder of Demon sword Gram

Moka Vladi
Pure blood Vampire Shinso
Rank supreme
Older sister of Gasper Vladi

Xun Er
Rank lord class goddess
Taoist Goddess leader of the Taoist Faction where sun wu Kong is from

Nyaruko
Rank: outer gods
Nyarlathotep Leader of the Lovecraftian Goddess
Perverted Anime otaku Best friend of Aika kiryuu

Kuroka and Shirone Toujo
Both will be twin sister and issei save them instead of the usual Canon stuff
Nekoshou yokai
Rank beast

Charlotte phenex Older sister of riser and Ravel phenex
Rank Supreme class devil
Won't discriminate against reincarnated devils unlike her brother riser

Titania
Rank Divine Class Fairy
Fairy queen ruler of the hidden Fairies Faction

I will leave the last 10 remaining slot for you readers to suggest who to be in the harem Remember NO RIAS and AKENO