Bacassi takes place in an alternate universe inspired by our modern world where demonic creatures live in peace with humans on earth facing the same economic and social issues.
This is all after the war where Equen Su, The Lord of All Demonic Dimensions, tries to forcefully take over and rule earth due to overpopulation and various forms of crisis in all the other dimensions.
Archangels from Heaven assign warriors marked by God named Nephilym to defend Earth from demons (Equelym). The devil loses the war, takes it out on his demons and they abandon him, migrating to earth after brokering a peace treaty.
Daemon, Shawna, and Wilton make up the new gang in town called “Bacassi”