The documents in Han Dong's hand have a large portion describing the "World Rubik's Cube."
The initial 'embryo' of the "World Rubik's Cube" alone gathers the highest technology of the Black Tower and the crystallization of wisdom, originally intended for more efficient storage and management of the multiverse.
However, the immature embryo completely fell into the hands of the out of control due to the fall of B.B.C,
by integrating various uncontrolled worlds into it and using unique means of the out of control for regulation, modification, and upgrades, they finally obtained the current World Rubik's Cube, which has surpassed the Black Tower in terms of technology.
During the visit to B.B.C, Han Dong was fortunate to have seen the World Rubik's Cube once under the guidance of Mr. Teacher.
He realized at the time that this thing was extraordinary, but he never thought that the Rubik's Cube would even possess "growth potential."
