Konoha Research Institute.
The floor covered in runes gave off a faint glow. At the center of the Jutsu Formula lay a person who had already lost all signs of life.
Tobirama stared at his latest failed creation, his brow tightly furrowed.
He had just conducted a soul transfer experiment, but the greatest problem remained: a soul could not stay in a new body for too long. Otherwise, it would be forcibly stripped from the body, and it would be unable to return to its original body as well.
How exactly did Orochimaru solve this problem...?
Orochimaru had left behind so many successful cases in the institute, yet Tobirama had never been able to reach a conclusion.
He had tried to create a secret technique capable of binding a soul, and he had succeeded. But the results showed that once the test subjects' souls remained in their new bodies for too long, they became agitated and uncontrollable. They wailed in pain without cease, gradually lost their sanity, and eventually died.
The test subjects had endured unimaginable suffering.
Tobirama felt as though he had entered some misunderstanding, going in circles without finding a way out.
He had considered whether his theory was wrong and starting over from scratch, but every time he reworked the deductions, this was the only theory that seemed feasible.
Completely at a loss, Tobirama left the institute and wandered aimlessly through the village.
After calming himself for a long while, he had no choice but to temporarily abandon his research on souls and turn instead to studying the Byakugan.
After several more days without leaving the house, he truly reached a conclusion.
If the Byakugan could evolve, then this evolution was not biological evolution. Rather, it was a change in the form Chakra took.
Otherwise, if an