天騎士オークに降る。

A demonic force has arisen from below to conquer the human race.
Since human society was exhausted due to the civil war, they were helpless against the evil hordes...
Opposed to the heaven's policy of non-intervention, a legion of celestial world comes down to assist humanity.

While they may have taken female human's appearance, they have godly powers to defeat the demonic forces. After the war, they became worshiped as the "Three Celestial Knightesses". But... after a while, these Knightesses abruptly disappear.