Bringing someone back from the dead was not beyond the realm of possibility.
Both Tobirama Senju and Hashirama Senju knew this. After all, one excelled at secret techniques, while the other could use Yang Release.
Tobirama Senju was, after all, someone who could get even the dead moving again. Though it was not true resurrection, he had taken that first step.
Given enough time to research it, there was no telling whether he might actually resurrect a dead person.
As for Hashirama Senju, that went without saying. Like Xia Yan, he could wield Yang Release.
Using Yang Release to ignite someone's life flame was indeed a way to bring them back to life.
But his method had the same limitation Xia Yan's once had: the person's life flame could not have gone out completely.
Once it had been completely extinguished, he might not actually be able to do it. When Xia Yan saved Minato Namikaze, he had acted before Minato's life flame went out entirely.
Regardless, possessing such an ability already proved that there were indeed ways to resurrect the dead.
But taking a "zombie" whose body was fundamentally someone else's, whose strength differed enormously from the original, and who was merely wrapped in impure paper, and turning that into a living person's body-
And making that body possess every function a normal person had-the difficulty was almost unimaginable.
Besides, such a resurrection would bring countless problems. The bloodline issue alone was enough to give anyone a headache.
Tobirama Senju also knew that a mismatch between soul and body would never lead to anything good.
He had reached that conclusion long, long before Orochimaru. It was hard to say whether Orochimaru's Reincarnation Technique had essentially drawn on Tobirama Senju's work.
Orochimaru was a prime example of someone whose body and