"That's right!" Cheng Tianhao nodded. "This is also one of the differences between true blood and mortal blood. The blood source of mortal blood usually comes from other martial artists in the Blood Martial Realm. It's relatively easy to obtain.
"As for the blood source of true blood, it can only be extracted from the blood beasts."
"Blood Beast?" Xiao Shi looked at Cheng Tianhao in confusion. He did not know what a blood beast was.
Cheng Tianhao immediately explained. "Blood Beasts are a kind of strange beast in the world. Most of the first generation blood sources come from Blood Beasts. However, there aren't many Blood Beasts left in the Tiandou Province. This makes Blood Beasts a very rare and important resource.
"It's said that a long time ago, the Swift Shadow Palace also raised blood beasts. But as time passed, the previous blood beasts were all exhausted. Now, there are no more Blood Beasts in the Swift Shadow Palace.