Prismatic Thunderball.

Wu Yu naturally had not heard of it before.

But he had heard of epochal immortal designs before.

They were above Void Immortal Designs, and the highest level of immortal designs. They were the perfect culmination of all, the final, boundless tier that immortal designs could reach. Many epochal immortal designs were created by nature itself, and not even the eternal immortal emperors could replicate them. Each epochal immortal design had a long history.

"It's said that epochal immortal designs have more than 10 billion spirit designs."

Wu Yu believed it. This Prismatic Thunderball before him had to have at least that number of spirit designs, or it would not be this frightening.

And perhaps only the Jade Emperor himself could casually create such a frightening epochal immortal design.

It was a miraculous existence.

Epochal immortal designs were legendary things, and today it was all too clear that they lived up to their reputation.

At least from what Wu Yu could see, this level of sophistication was far beyond what he was capable of. The truism went that there was always a higher mountain. The eternal immortal emperors'...