Edo Tensei
After gathering enough living sacrifice, Ren Tianyou used kamui and arrived on an isolated island in the middle of the ocean, and began the preparation of Edo Tensei.
As stated before, this Edo Tensei was the forbidden summoning jutsu developed by Second Hokage Senju Tobirama. This jutsu could summon the soul of deceased person back to the living world and resurrect them by binding it to the living person. Afterwards this jutsu was improved by Orochimaru, and Kabuto brought it to the greatest height of development, but this jutsu however had three necessary prerequisites. They were:
First of all, the DNA of the person to be resurrected was required. If this condition wasn’t be satisfied, then there was no way to resurrect; (i.e. a piece of human body of intended reincarnated was absolute necessity)
Afterwards a living person was required to use as a sacrifice to become the vessel of the intended reincarnated.
The soul of the intended reincarnated must reside in the Pure Land; if the soul was sealed, then it couldn’t be summoned.
After this jutsu is used, the dust and ash would encase the body of the sacrifice, giving them the same appearance as the reincarnated had before the time of their death;
In Edo Tensei, although the jutsu user could restrain their movements, but the soul of reincarnated people could still free themselves if they were greatly stimulated in some emotional way. To prevent this from happening, the jutsu user could implant their control talisman in their brain, and completely wipe out the reincarnated soul’s personality, making them have no sense of self, and turning into merely a killing tool. But like this, although the control over the reincarnated soul would strengthen, but they would be less resourceful and they required the attention of summoner for every action, reducing their strength.
Furthermore, those person reincarnated with the use of Edo Tensei couldn’t be killed with any method, in other words, they obtain immortal body.
As far as the understanding of Ren Tianyou, there were only few ways to end this Edo Tensei jutsu!
The jutsu caster himself end the technique (on his own accord or forced). This is the most fundamental way to end this jutsu.
Sealing the body of reincarnated soul. This can only stop the action of reincarnated soul, but the Edo Tensei jutsu in itself will not end.
Remove the soul from the reincarnated body and seal it (such as with Shiki Fujin (Sealing Jutsu—-Reaper Death Seal)). Then the Edo Tensei jutsu will automatically end. And after the soul itself is sealed, Edo Tensei will not be able to resurrect them again. Such the first hokage, second hokage and so on.
If the resurrected person still retains their personality, and had will that is sufficiently strong, then the soul might be able to struggle free from the binding and ascend to heaven. After that the Elo Tensei jutsu will automatically end. Such as Sasori.
Seize the control from the jutsu caster (only know method is Kotoamatsukami (Distinguished Heavenly Gods), but the Edo Tensei jutsu in itself isn’t ended, and summoning contract still exist. Such as Uchiha Itachi.
If the reincarnated person knows required hand seals of the Edo Tensei jutsu, then they could completely free themselves from the influence of Edo Tensei as well as free themselves from the summoning contract of Edo Tensei. Afterwards, they would be no longer under the control of jutsu user. Such Uchiha Madara.
Thoroughly destroy the physical body of reincarnated soul (only Yin-Yang style could accomplish it), but what would happen to soul, he didn’t know.
If the resurrected deceased person is truly revived (only Rinnegan’s Rinne Rebirth Jutsu can accomplish this), then Edo Tensei Jutsu would naturally end.
Moreover this Edo Tensei also had a small flaw, and that was, no matter how much skilled one was in this technique, there was no way to way to make the strength of the reincarnated person achieve their peak strength before their death, can only reach infinitely close!
Furthermore if the gap between the strength of the reincarnated person and the jutsu user was too big, then the jutsu user might not be able to control the reincarnated person, and get himself killed by the reincarnated person. But now Ren Tianyou had already refined the power of Forever Green completely, so his binding power would naturally be very strong, as a result, these reincarnated person would not be able to easily struggle free from his binding.
………………..
Standing on a mountain peak, the sharingan of Ren Tianyou spun rapidly. Then along with the appearance of spiral shaped space ripple, two human figures appeared in front of Ren Tianyou.
Two middle-aged man with ferocious looking face and wearing cotton clothes knelt on the ground in front of Ren Tianyou. Right now their hands were tied behind them, and theirs eyes didn’t have any spirit.
These living sacrifices, from the time they were sucked into the kamui space, they had been under the illusion of Ren Tianyou, so there was no resistance.
Ren Tianyou walked to that relatively big build middle-aged bandit, then stretching his hand, he directly twisted his neck, ending his sinful life.
Shortly afterwards, RenTianyou took out a kunai, and directly stabbed the chest of this dead middle-aged bandit. Along with ‘puchi’ sound, red blood splashed in all direction from his body!
And Ren Tianyou exerted some strength in the kunai and took out a piece of bloody flesh on the tip of kunai!
“Well, the DNA is ready!” Looking at the bloody flesh on kunai, Ren Tianyou muttered.
Yes, Ren Tianyou wanted to reincarnate this bandit in front of him first, as now was only an experiment, so how could he take chances with those precious corpses of experts.
“Now it’s time to use this fellow as an offering to summon the deceased.” Ren Tianyou slowly thought.
He naturally understood the formula of Edo Tensei perfectly. So, he walked to that remaining bandit who was the sacrifice, and not far away from him, he began to make a series of hand seals quickly.
“Tiger-Snake-Dog-Dragon!” Along with the hand seals of Ren Tianyou, huge black colored mysterious formula appeared on the ground in front of him, then rapidly spread, spread to that sacrifice bandit.
And in the middle location of this formula, four blank circles appeared. And in these circles, 秽－土－转－生 (Edo Tensei) these four large characters appeared.
Shortly afterwards, Ren Tianyou clapped his hand together, then along with the circulation of chakra within his body, he lightly said, “Kuchiyose—-Edo Tensei! (Summoning Jutsu—-Reanimation!)”
Along with the voice of Ren Tianyou, suddenly white light rose from the body of that sacrifice bandit, then countless dust and ash that appeared from the formula on the ground encased the body of this bandit.
Along with the appearance of dust and ash, this bandit sobered up from the illusion, then gave out a horrible shriek in pain.
After the dust and ash disappeared, this sacrifice bandit’s appearance had already changed into the appearance of the bandit that had died just a moment ago.
“This……this is?” Feeling he could breathe fresh air again, and difference within his body, this resurrected bandit involuntarily exclaimed in surprise.
“Never thought I would succeed in my first try, don’t tell me that it is not difficult to learn this Edo Tensei jutsu?” Seeing he had successfully resurrected a person, Ren Tianyou exclaimed in surprise within his heart.
But Ren Tianyou didn’t think about these matters for the time being, rather walked forward, and then implanted a talisman into his head. After that he wiped out his personality, making him merely a killing tool without any thoughts.
After doing this, Ren Tianyou controlled this reincarnated person for experiment, and made him use his strongest attack move. Several minutes later, Ren Tianyou understood a number of things from his experiment and his own conjecture.
According to his conjecture, the reason why this Edo Tensei jutsu was used by only a few number of people in Naruto world was because most of the people basically didn’t know the method to use this Edo Tensei Jutsu! Thinking about it, the higher ups of Hidden Leaf weren’t idiots, they naturally were clear about the might of this Edo Tensei, as this jutsu user could create a group of powerful immortal army, just like Kabuto who had created that luxurious line up where the BOSS level characters of Naruto were resurrected. So the higher ups of Hidden Leaf might have strictly controlled this jutsu. And at that time’s Third Hokage might have felt that this jutsu defied the heaven and blaspheme the soul of deceased, so decided to forbid anyone from studying this jutsu.
And this jutsu might have been accidently discovered by Orochimaru before he defected, and learnt it. And as a faithful aide of Orochimaru, Kabuto also naturally learnt this jutsu.
But although this Edo Tensei Jutsu was easy to learn, it however was very difficult to master. After experimenting the strength of the resurrected person just now, he discovered that although this resurrected person had Great Swords Master ranked strength before his death, but now after resurrecting, he could merely display the attack strength of Great Swordsman rank at most, falling nearly two great rank!
Just like that time, when Orochimaru planned to destroy Hidden Leaf, those grand First Hokage Senju Hasirama who was known as God of Shinobi and Second Hokage Senju Tobirama were unexpectedly sealed by Third Hokage. At that time when Ren Tianyou had seen this, he’d felt a burst pain in the ass.
Thinking about it now, it seems Orochimaru might have just mastered this Edo Tensei at that time, and was insufficiently skilled in it, so after First Hokage and Second Hokage were resurrected by Edo Tensei, their actual strength was very low compared to their actual strength before their death. As a result this old fellow Third Hokage was able to seal both First Hokage and Second Hokage. And now Ren Tianyou was in similar state, he was very far from being sufficiently skilled in this Edo Tensei Jutsu, so he still needs more practice.