The White Bone Yin Demon Banner actually could not be directly "copied" in Taiyuan's Login Hall.
Yet the second-tier Windfire Bone Blade, likewise refined from spirit bones, posed no problem at all.
Wang Yu turned one hand over, and the newly condensed Windfire Bone Blade vanished. With his other hand, he pointed into the empty air before him, and a White Bone Skeleton slowly began to condense from the feet up.
But just as the skeleton formed up to its waist, it too blurred and disintegrated.
Wang Yu patted his forehead, a thoughtful look appearing on his face.
In fact, he had discovered several years ago that not only the fused White Bone Yin Demon Banner, but even the White Bone Fiend and Yin Soul Banner he had personally refined could not be copied in the Login Hall.
This overturned what he had always believed to be an absolute rule: any magical artifact he personally refined could be copied in this space.
If the main material was the reason, then why could the Windfire Bone Blade, also refined from spirit bones, still be easily "created"? If there was any difference between them, it was "yin energy."
Whether the White Bone Fiend, the Yin Soul Banner, or even the later White Bone Yin Demon Banner, all had incorporated vast quantities of yin energy during their refinement. With enough yin energy to nourish them afterward, they even had the potential to advance on their own.
Could this be why they couldn't be copied in the Login Hall?
Judging by the records and descriptions in various ancient texts, yin energy was indeed rather unusual.
Not only was it a mutation of heaven and earth spiritual energy, but places where yin energy lingered for long periods would also give birth to yin spirits-the same