Apart from the one regular face that could be used long-term, the four-faced individual's remaining three faces had a time limit when they were activated.
The handful of individuals who knew about his four modes had more or less guessed that this was the case. However, they thought the reason for this restriction was that activating different modes would put a heavy burden on the four-faced individual's physical body and spirit.
Meanwhile, the four-faced individual was the only one who knew that this was not the case.
In reality, each of his faces was an entirely different personality.
The dominant personality was his regular face, which maintained the balance between the other three personalities.
At present, his four personalities could maintain a state of equilibrium mainly because of this regular dominant character.
However, every time he changed a face, he needed to let that particular personality out.