Simply put, this world is somewhat similar to Naruse Mio's world, where there are two factions: Angels and Demons. The Deity's Angels and the Demon Army are engaged in an eternal battle. As for the Humans, they become the wedge caught between the fighting sides. Similarly, the Angels and Demons also use Humans to enhance their Strength.
However, unlike Tower City Kitten and Murasakifuji Ilina, who were reborn as demons or angels, on the angel side, they primarily use guidance and leadership to make strong individuals among Humans stand with them against the Demons. After all, if the Demons win, then Humans would be entirely enslaved by the Demons. In this situation, Humans naturally stand on the side of the Angel Camp and launch an offensive against the Demons.
