Power Play!

An evil king, Shadalh, is trying to gather all the beautiful girls in the world to his harem, but the three magical (female) knights intervene with his plans and his familiar is forced to save him with teleportation (by mistake reincarnation) magic.
Story continues as in front of ex-evil king, now Sadaharu, 28 years old virgin, his familiar, Sara, falls from the sky and transforms into a brown, silver haired beauty.