The forbidden spirit-summoning book Song of Chanting, sealed away for generations by the Black Moon Cult since the Middle Ages, has been stolen. Mysterious black magic and over a hundred kinds of combat summoning arts have entered the world, plunging the once peaceful continent into turmoil. In an effort to resist the unknown summoning arts, humanity developed gigantic aberrant creatures, but the technology was still immature and they went out of control. More and more “monsters” appeared across the seas, in forests, and in the wilderness. As military weapons proved increasingly incapable of dealing with the activity and destructive power of these mutated creatures, people began trying to use the Black Moon Cult’s summoning arts to fight the giant monsters. As time went on, a true demon-hunting corps rose to the forefront of the battle against aberrant creatures: the Royal Stewards, a global mercenary organization of pact-bound summoners, backed by the Sansed royal family and founded by Archibald, former Second Bishop of the Black Moon Island Cult.
