A Foundation Establishment Realm soul was likely stronger than the souls of ten thousand Red Soul Bone Beasts combined!
But Cang Songzi wasn't an Undead, and his soul had just left his body. It had no power to resist and could only be devoured by the Little Gray Skeleton.
If an ordinary Undead Creature could devour the soul of a Foundation Establishment Realm Cultivator, it could probably advance to the Perfect Red Soul Realm.
The Realms of Undead Creatures were divided according to the color of their Soul Fire.
Gray, Red, Cyan, Blue, and Purple were the five major Realms. The higher one climbed, the harder it was to advance, requiring an almost oceanic amount of souls to be devoured.
A Gray Soul might only need to devour a hundred of its own kind to advance to an ordinary Basic-level Red Soul. But for the lowest-level Red Soul to advance to a Cyan Soul, it was hard to say if even a hundred thousand or a million same-level souls would be enough.
