- “You’re immoral! Simply too wicked! My life’s mission is definitely to convert you, you sinister bird!„
Its given name is Ultimate Vexation, coined by an unknown "old friend" in ancient times. It is unaware of why its name is Ultimate Vexation. Meng Hao usually refers to him as meat jelly, while he calls himself Lord Third naming himself after Lord Fifth, as he can only count to three.
His greatest wish in life is to convert every immoral being. He says that his greatest nemesis is Lord Fifth because he has spent countless years trying to convert him all to no avail. He likes to eat lightning to a certain extent; when Meng Hao was undergoing a Tribulation he used him as a shield, which caused him to be scared of Meng Hao.
While in its free state, it looks like a meat jelly, but during its time with Meng Hao it transformed itself into a hat. After Meng Hao unsealed Lord Fifth he donned the appearance of a bell that hung on Lord Fifth's foot. As it can freely change appearances and can transform to almost anything, Meng Hao often used Ultimate Vexation as a body armor due to its indestructible form.
Eons past before the Vast Expanse came into being, the Ancient-Immortal spirit alongside Allheaven was forced into dire straits by Lord Fifth, a subordinate of the enemy of The Immortal; Allheaven's true body. Seeing no other way out, Allheaven then forced the Ancient-Immortal into self-detonating, but contrary to expectations she instead unleashed a Nirvanic Rebirth Curse — an absolute and perfect disintegration of the body and the will. The final technique she released was something that created a new epoch, a new world and a new beginning. Within that new world, a reincarnation of the Ancient-Immortal was born, the woman was unaware of her previous life and was sent to the cycle of reincarnation over and over again for incalculable epochs, experiencing numerous lives. It was then fated that she met a person in one of the tinier worlds within the Vast Expanse, the Paragon Immortal Realm. That person would come to be called the Lightning Emperor. He came to love her and would later become the woman's husband.
The lower realms of the Paragon Immortal Realm rebelled, incited by the actions of Allheaven. The Lightning Emperor fought for his home, for his people and for the woman he loved and cherished. The battle would span thousands of years, causing massive counts of deaths, the Lightning Emperor amongst them. After dying, innumerable lightning bolts from his body was sent out causing tremors in the entire area. His wife wept by his side, her tears falling down on his armor. In that moment of grief, her previous life's memories were unsealed. As her tears vanished, so did her feelings for the Lightning Emperor. She departed, never to be seen again.
The corpse continued to soar high above the starry skies of the Paragon Immortal Realm, eventually becoming translucent. Because of the tears shed by the Ancient-Immortal's reincarantion, the corpse gradually merged with the armor. His soul, which should have died fully fused with the armor. After countless years, he would awaken knowing he became an undying being. He knew that he must never again risk his life for someone, for it would lose its undying nature. He had no memories of his past. He discovered that he had a fondness for civilizing bullies and the wicked. He wandered around the Mountain and Sea Realm for many years doing so where he would later run into Lord Fifth — a mischievous parrot he would swear his life for to convert. He would also later meet Meng Hao, a cultivator who forever changed his fate. 
Not one knows of its origin but it was found by Meng Hao and Han Bei sealed away in the Black Sieve Sect's Ancient Blessed Land. It first appeared in the shape of meat jelly, and was eating Tribulation Lightning. After a brief encounter with Meng Hao, it complained about Meng Hao having "that bird's qi" on him and promptly threw up. 
Meng Hao later discovered that the Black Sieve Sect wanted to capture and use Ultimate Vexation for nefarious purposes. Out of desperation Ultimate Vexation bonded itself to Meng Hao after which the two of them teleported to safety. 
Meng Hao soon learned the meaning of its name; it can talk incessantly to the point of driving a person crazy. Meng Hao deals with this by sending Ultimate Vexation into the Blood Mask to convert the Li Clan Patriarch. Later Meng Hao wanted to borrow its shape changing abilities to infiltrate into the Violet Fate Sect, for the price of three bullies to convert. 
At one point soon after arriving in the Violet Fate Sect, it had to disable its shape changing ability because it had to shed. The process takes a month, after which it explodes out, leaving an indestructible shed skin behind that Meng Hao collects to use in various ways.
When seeing it for the first time, Paragon Sea Dream talks about a man known as the "Lightning Emperor" and the meat jelly had a strange reaction to it. 
After becoming an Allheaven Dao Immortal, Meng Hao became able to equip the copper mirror as a weapon, with the meat jelly becoming the battle armor, and the Blood Mastiff transforming into a cape. 
After the remnants of the Mountain and Sea Realm managed to reach the Green Coffin Vortex (a supposed safe haven), Meng Hao stayed back to defend against the Immortal God Continent and the Devil Realm. During the battle, Meng Hao was in a grave crisis and at that point his life was destined to end. However, the meat jelly sacrificed all of its life essence to teleport Meng Hao away, while Lord Fifth gave up its sentience to stall the two powers. After that Lord Fifth left to travel tens of thousands of worlds before he could return. After this event, the Meat Jelly is assumed dead and Lord Fifth a spirit automaton of the Copper Mirror. 
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