The demonic, and angelic people were and still are a natural threat to each other. Some years ago they tried finding a way to live in harmony but of course most of the majority of both sides didn't agree with trying live in each others realms because if either side of the demonic or angelic kingdoms were to stay a long period of time in the others realm they would get seriously sick, and eventually die. So the majority of both kingdoms went against the head of the kingdoms and started a war. Both leaders of the kingdoms were convinced that the opposite side plotted an attack against them, thus ruining any chance in trying to be ally's. As the years go by a few battles break out over spies being caught, an a couple curios wanderers, of course all battles ended with either one or the other side winning but they would always just go back to the kingdoms because they figured if one's gone, what would stir them up in the future?