Gu Tieshou ordered to rearrange the Scripture Library, the Weapon Armory, and the Treasure House and found this mysterious Ancient Tablet. Li Qiye recognized the symbols on it and decided to take it away.
It escaped/was lured out by something, into the lightning filled void in between the 10th World and the non-existing world. 
As an Ancient Tablet it was pitch black without any light. The top was etched with clear engravings, they were complex to the point of being burdensome. This tablet had experienced an unknown amount of years and was filled with holes on top. This was not due to the erosion of time but rather sword markings.
After transformation it became a stone egg.[?]
Even Li Qiye doesn't know about its actual origin or strength. Its eggshell is harder than Divine Metals, so, currently, Li Qiye uses it as a blunt weapon sometimes. The Myriad Star Egg can smash apart even the space.