The Retired King of the Demon's Castle / 魔王城の隠居参謀

In a world where demons can only reproduce through human women, you have been serving the previous demon king as his advisor.
And you used to serve the previous demon king as his advisor, but now you are serving the new demon king, Satana, after the previous demon king retired.
However, the demons have abandoned Satana, who cannot breed because she is a woman.
Help Satana regain her power by humiliating the Demon King's defeating team that comes to the castle.
It's up to you, the last servant, to sire the Demon King's strike force!