Genma Wars: Eve of Mythology

In the far distant future, hideous monsters roam the Earth, threatening the lives of all people. Genma, the evil ruler of the Mah tribe, has become obsessed with fathering an Heir. Convinced that a child born of a Hito woman will have amazing powers, he sets his sights on a young Hito woman. In exchange for her village's safety, Non agree to bear Genma's child. She gives birth to twins and names them Loof and Jin. Jin is left for Non to raise among the Hito, as Loof is taken to Genma, and raised to be the prince of the Mah tribe. Although Loof and Jin live in two separate worlds, their fates soon become intertwined as Loof is banished from Mah tribe once he appears to possess more human than wizard physical characteristics.

Super sadly this is the only one of its kind