The Demon Reunion

Chaos opens, heaven and earth are divided, a world of one side, a legend through the ages. Contracts, partners, monster fights, in this world there are monsters, beast monsters, spirit monsters, strange monsters, elemental monsters... Human beings form a contract with them and become monster masters. The demon master can not only summon demons to control demons, but can also borrow spiritual contracts to transform into saints and become a legend of his own. To become a demon master, you should not be limited to one world. There is a world beyond that, very, very big...