Quote Originally Posted by Skytotem View Post
That'd be neat, but he looks... alive-ish aside from the red eyes.
Maybe just a group of humans (Lordaeron) leave the alliance and join the horde or maybe from the Universe where Adaelas conquered the alliance while he commanded the orcs and he named it the horde and tada! we got Horde Arthas

Note: That universe actually appeared in one book (The hour of Twillight), where Arthas never became the LK, the horde was never created and the alliance is controlled by Adaelas (the orcs are part of the alliance)