Su Ping's own bloodline—of the Primitive Chaos Clan—was a combination of gods, the soul race and ancient deities. So, he wasn't surprised that a constitution could be improved by absorbing more bloodlines, although this seemed to be confidential in the Federation.
Combining bloodlines was extremely risky; one could lose control and die easily without the right recipe.
It was very likely a forbidden cultivation method in the Federation.
As expected of an emperor-level sutra. The practitioner can reach the highest level, the God Emperor state!
Unfortunately, these arts require too many sacrifices; the processes are too gory and cruel. It would be perfect in war times, where there are plenty of bodies lying around.
Su Ping skipped the cultivation techniques and kept reading. Some secrets popped up soon after.
The Age of Emperors' Fall?