Although Sea God Poseidon and Western Underworld King Hades had snuck into the Demon City, these two chaps thought their security measures were pretty darn good and that there'd be no so-called 'incident exposure', in other words, being discovered and dragged out into the open.
But, these two deities from the West still oversimplified things, truly too young, too simple.
Ever since he found out that the Eastern Female Death God, whom he had an eye on, Empress Shangguan Linlang, had set her heart on marrying the Lord of Demon City, Xuanyuan Wuji, with whom our Empress Shangguan Linlang had long made a pact, the Western Demon King Satan naturally felt all sorts of downcast, all sorts of gloomy, all sorts of itching to punch someone, oh my.
