As for the reason, neither the Heavenly Martial Ancestor nor the Star River Ancestor knew. No matter how they studied it or cultivated it, they simply could not master it.
After all, this was a secret art from the Spirit Venerable's inheritance!
And the Spirit Venerable was one of the Origin World's four divine envoys, a true supreme expert of the Origin World era. In the present day, he would have been a terrifying existence at the very pinnacle of the Heavensea.
If they could cultivate it...
Why would the Heavenly Martial Ancestor and the Star River Ancestor ever choose not to?
Aside from that, there was the matter of the Heavenly Derivation Book's completeness.
The Heavenly Martial Ancestor and the Star River Ancestor did indeed know of the Heavenly Derivation Book, but they possessed only its First Layer, not its Second Layer or third.
As for Qin Hao...
The two ancestors knew without even thinking about it that, since Qin Hao had received the inherited secret art directly from the Spirit Venerable, he surely possessed the complete art, not merely its First Layer.
That alone was enough to show how precious the Heavenly Derivation Book in Qin Hao's possession was, let alone the fact that he had already made progress in cultivating it.
It could certainly be put this way.
To the many supreme experts, the Heavenly Derivation Book was an extraordinarily impressive secret art, yet it offered them no benefit.
To Qin Hao, however, it was immensely useful.
All because Qin Hao had mastered it!
He had already crossed its threshold!
"So the Heavenly Derivation Book my Big Brother received is still incredibly useful!" Yun Chang immediately brightened at those words.
Neither the Heavenly Martial Ancestor nor the Star River Ancestor mastered it? Qin Hao's heart stirred as