Inverted Sky Lord

The Inverted Sky Lord is the overarching main antagonist of the entire story, the Cult Leader and God of the Cult of the Inverted Sky, and through the cult is singlehandedly responsible for all of the machinations within the entire story. It is revealed that he is the direct descendant of the Soul Sky of the Five Skies, and the first true deity within the story. His full name is not revealed.

He was the strongest living character in the series at half-step Mythical Being Realm. Shortly after he is introduced, he gets used to his new puppet's body after the Emperor's body is beheaded and breaks through to the Mythical Being realm, easily overpowering Hyuk Woon Sung, the Sword Star, and the Buddhist Star singlehandedly. He is capable of smashing the Sword and Buddhist Stars limbs easily and breaking their swords all while Hyuk Woon Sung was unconscious for a few minutes. He also has incredible durability, as he is able to tank one of Hyuk Woon Sung's strongest techniques without ever so batting an eye.

The Inverted Sky Lord is very familiar with manipulating souls and aura, to the point where he is the only character in the story that was able to tell that Hyuk Woon Sung went through reincarnation with a single glance. He is also capable of changing how he sounds from a man, woman, or child, and can cover the sky in gray aura giving it an inverted appearance befitting of his title and cult. The name of the corpse puppet he uses at the end of the story is "Divine Corpse Puppet Gu".

Ultimately, he meets his end at the hands of the Divine Heavenly Demon after Hyuk Woon Sung breaks through to the Mythical Being Realm through a second body reformation and creating the ultimate zenith of all of his accumulated martial arts, the Heaven-Shattering Martial Supreme/Heaven-Breaking Martial Ultimate (天绝武极). He is killed with a single thrust of the Heaven-Breaking Martial Ultimate technique through the heart.

A young man with white hair and fair skin.

Although handsome, it felt like he would be difficult to approach, giving off a sharp presence.

If we gave the intangible thing called Death a shape and called a skilled sculptor to mold it into human form, wouldn’t it look like him?

History
The Inverted Sky Lord was born a regular human who rose to the highest peaks of martial arts through the use of Divine Being corpse puppets and mythical elixirs. Through drastically training his strong soul and possessing the body of a peerless Divine Being corpse puppet, he became a peak Divine Being realm expert, essentially half-step into becoming a true deity through the Mythical Being Realm.

At that level, no matter how strong the Cult of the Heavenly Demon and the World Ending Heavenly Demon were, they would be no match.