After some deliberation, Casio's thoughts became lucid.
Perhaps, there really is a certain possibility.
Dark creatures have a means of parasitizing humans, such as the Shadow Demon and Dead Blood that Casio has encountered. Take Dead Blood as an example. He massacred and absorbed large amounts of Dead Blood during the Era of Retrospection, so he has a certain understanding of its unique life characteristics.
In the Blood Spirit Association, lower-level members generally shared a symbiotic relationship with Dead Blood and human. By the middle tier, the Dead Blood had completely taken over the host body. This is even more so at the senior level, where the original human has become a walking corpse, a mere vessel.
When absorbing the life vibration energy, Casio noticed a common phenomenon. That is, the assimilation of the 'Life Field'!
The human life field of the human body is gradually influenced by the life field of Dead Blood, their frequency fluctuations becoming similar.
