Having figured out the whole story, Stark immediately began studying the fierce ghost Nick had sent over. But his approach to researching ghosts was definitely different from that of mages—he believed in scientific analysis.
After conducting many sets of experiments, Stark discovered that ghosts were not actually that mysterious. At the end of the day, they were still related to Earth's magnetic field.
As everyone knew, Earth was a very special planet in the Solar System, and its most special feature was its magnetic field. To some extent, Earth's unique magnetic field was the greatest reason it had become the only planet in the Solar System to evolve life.
However, most creatures on Earth could not perceive magnetic fields. A small number might instinctively respond to them, breeding and living according to changes in the magnetic field, but almost none could see this mysterious force with their naked eyes.
But once Earth's technology began developing rapidly, many scientists turned their attention toward this mysterious field. They discovered that humans had become the only life form possessed of advanced intelligence—or rather, the root reason human intelligence far surpassed that of all other creatures might be that human brainwaves reacted in some way with Earth's magnetic field. From this, the theory of the soul could also be derived.
This led Stark to wonder: if a person's brainwaves could exist independently after leaving the body, would they become a ghost?
But Mephisto denied this. In the words of the Lord of Hell, so-called brainwaves were actually the soul.
On Earth, human souls could almost never exist independently of their bodies. Only after the body died could the soul remain for a short while.
Ghosts were different. Their souls had undergone a certain mutation—what Stark called retuning—which allowed them to remain on Earth for