"That guy is even the strongest among the Four Heavenly Kings... no wait, the strongest... guhhhhhh!!"

"He's the weakest of the Four Heavenly Kings." When did this become standard? It's a given that happens when the first of the Four Heavenly Kings is defeated. In an era when it had become an established catchphrase, the brave party finally stormed into the Demon King's castle. Sordi the Invisible, one of the Four Heavenly Kings, stands alone against the brave party. Behold! The life of Sordi the Invisible, the man called the weakest among the Demon King's army's Four Heavenly Kings!