This method of breeding Ghost soul beasts was of vital importance to the Ghost Empire. Back then, the Ghost Empire had risen to power precisely because it mastered this method. If it had not made too many enemies, it would not have ended up like this—perhaps it might even still exist today.
Now that Zhao Fu had obtained this method, he naturally had to make full use of it. He could not let something so valuable go to waste.
Lastly came the materials needed to breed Ghost soul beasts: people. Wild beasts could also be made into Ghost soul beasts, but their intelligence was low, and the resentment they generated was not great. It was comparatively difficult for them to form into Ghost soul beasts, and even if they did, they would not be very powerful.
Thus, the most suitable materials for Ghost soul beasts were countless people. Using people as materials made Ghost soul beasts easier to create, and their quality would also be higher.
Zhao Fu had originally wanted to directly cultivate five hundred million Ghost soul beasts, but no war was currently taking place, and there were not that many people available to make into Ghost soul beasts.
Naturally, it was absolutely impossible to use Great Qin's citizens to make these Ghost soul beasts.
The insect beasts of the Chaos World could not be used as materials, nor could the people of the Alchemy World. Moreover, Great Qin was currently being suppressed by the Alchemy World and had no ability whatsoever to expand outward, much less plunder a massive number of Alchemy World inhabitants.
The only remaining battlefields were the Netherworld battlefield and the Apocalypse battlefield. The people there were more suitable.
The most suitable of all were still the Netherworld's inhabitants, because they were inherently yin-attributed.