On the continent of Rondeval and its neighboring Vaxi Island, humans live alongside powerful creatures. Though some are as intelligent or more so than humans, while others are simply strong wild beasts, humans refer to them all as "monsters". On this continent the Sygh-Varths empire has held power for 336 years, but is now faced with a crisis that threatens to tear it apart.
Its 12th emperor, Haysheen, has proven to be a tyrannical ruler, taxing the people to near-poverty in order to increase the wealth and power of himself and his underlings. There is hope, however- a resistance group, led by a young, capable leader named Yugi, has begun to fight back against Haysheen. The war is waged by human marshals trained to direct monsters in battle. Yugi and his allies fight for the freedom of humans and monsters alike.
The strongest side will win… let the game of battle begin!