Ji Xiuning is Ji Xiuning, and Old Fourth is Old Fourth, even if they occupy the same body.
The Hell Knight Old Fourth, unknown how many generations it has been lurking, its research on the human brain domain surpasses nearly everyone, including Demon Emperor Lanling, including the Dragon Temple.
The complexity of the human brain domain is comparable to the entire universe. The known brain domain, the developed brain domain, is less than ten percent, while the remaining ninety percent, although operational as in discharging, instincts, etc...
But that ninety percent of the brain domain is like countless dark nebulae deep within the universe, entirely mysterious and unknown.
And the Hell Knight Old Fourth mainly lurks within this unknown brain domain.
Also, every time it lurks, it's before the target enters the Dragon Temple.
For instance, this generation's target, Ji Xiuning, was merely a few years old when Old Fourth's soul lurked into her unknown brain domain.
