A very special kind of power was needed during the cultivation process.
It was named—[Demonic Evil Thought]!
By chanting the secret incantation at a specific hour each day, one could draw Demonic Evil Thought from the unseen Demonic Realm to descend upon oneself, slowly seeping through the fleshly body and transforming it into a demonic fetus.
The process was extremely dangerous. One careless slip, and it might draw a heavenly demon over.
At best, it would bewitch the heart, causing one's temperament to change drastically.
At worst, it would seize the body, which was no different from death.
The concept of a heavenly demon was very similar to an inner demon, yet also completely different. The source of a cultivator's inner demon was often their own obsession, with a source that could be traced.
But heavenly demons, aside from being formless and shapeless and hard to detect, were also special lifeforms from beyond the realm—extraterritorial beings.
Unless they took the initiative, it was very difficult for cultivators to become entangled with heavenly demons.
And this was only the first step of the [Demonic Fetus Profound Origin Secret Incantation]. After cultivating the Profound Origin Demonic Fetus, the second step was to seek a target—the closer the blood relation, the better.
Using one's own demonic fetus to plant a demonic thought, one would imitate the process of Heavenly Demon Body Snatching and devour everything of a person of the same bloodline origin until not even dregs remained.
Most importantly, this secret incantation could be used continuously.
Even those who were not of the same bloodline origin could also be devoured, but there were many more restrictions. For example, the demonic thought was difficult to plant, it was hard to thoroughly seep in and taint them, and even if the devouring ultimately succeeded,