The Ghost King was so enamored with the Demon Blade Maple that he made it his sidearm.
If the story ended here, it would have been a perfect tale, but what unfolded afterward was beyond anyone's expectations.
Decades ago, a demon-slaying operation was held in Heian-kyo, where many samurai and onmyoji formed a coalition to attack Monster Mountain, aiming to exterminate all the Hyakki there.
As for why they hunted demons, there was no reason; it was simply the elders' boredom leading them to want a hunt.
Fortunately, Shuten Douji, the Ghost King, was already on Monster Mountain at that time, so under his leadership, the Hyakki began organized resistance.
Although the leader of the demon-slaying team, a woman named Minamoto no Yorimitsu, was very powerful, Shuten Douji was not afraid of her. The two fought for a long time, and in the end, neither could subdue the other.