This process was exceptionally perilous.
The soul, after all, was an inherently fragile thing. Even the slightest injury could render a person unconscious, or even kill them outright.
Even for a Wizard, the soul was their single greatest weakness.
During the process of fusing the soul with Elemental Fire, the slightest mistake could cause rejection. In a mild case, the advancement would fail and the soul would be damaged, requiring a great deal of time and effort to recuperate. In a severe case, the soul would be left incomplete, completely severing any possibility of a future breakthrough.
Therefore, every Level 4 Wizard was exceedingly cautious about fusing their soul with Elemental Fire.
They would rather spend several hundred more years preparing at the fourth level than dare to attempt a breakthrough rashly.
This was why the Soul Fusion Potion, which could reduce the chances of rejection during fusion, became a treasure that many Level 4 Wizards dreamed of obtaining.
