Cablax Kingdom's ninth prince, Zain Dunn, was born with an Innate Divine Bone and cultivated all the way to the Ultimate Realm. In a battle against the primordial ferocious beast, the Devouring Beast, he emerged victorious and sealed it within the Reincarnation Tower.
Yet after his victory, the third prince, Riley Dunn, joined forces with Consort Marie Hale to poison him. While Zain was unconscious, they had him dragged to the Dragonbane Grounds and publicly framed him with fabricated evidence of treason. Under the decree of his father, King Henry Dunn, he was subjected to the punishment of having his Divine Bone extracted.
His Divine Bone was forcibly ripped from his body, causing his Mystic Wheel to shatter completely. Zain fell from being a Supreme chosen by fate to a powerless cripple. He was then thrown into the storeroom of the Martial King's Manor, left to live or die on his own.
At that moment, the mysterious black ancient tower within Zain’s body, the Umbral Tower, awakened and drew him inside. The Devouring Beast appeared, revealing the truth behind his Primordial Ancient Physique and reforging Zain's Mystic Wheel.