Fujin continued analyzing, 'Of course, such efficiency comes only after discarding the lives of Root ninjas. The second seal shows the willingness of Hiruzen and Danzo to sacrifice them without a second thought.
Though it is rather brutal to sacrifice your own ninja, I can understand why Hiruzen would allow Danzo to do so. If the situation becomes that bad, then it already means that the Root ninja is more or less dead. He will just be tortured until they can get all the information from him.
By choosing to sacrifice his life and using that chance to counterattack the enemy, the enemy will be far more reluctant in trying to capture and torture any Konoha ninja, even more so if the captured ninja is an Anbu. This way, at least the final moments of the ninjas won't be filled with torture and blaming themselves for compromising the safety of the village or their friends.
Of course, the biggest reason why Hiruzen allowed Danzo to use these two seals is because Danzo doesn't have any control over these two seals other than being able to put them and release them. Unlike the Hyuga clan's curse seal, these two seals don't have any features to allow Danzo to paralyze a Root ninja or to destroy his brain at will.
As long as the Root ninja is safe and doesn't intend to divulge any information, even Danzo can't use the seal to control or torture them. He will have to depend on his other skills to do so. Only… I wonder if Danzo created the seals in such a way to ensure that Hiruzen would agree or if there are any restrictions due to him being able to include his imprint in the seal.
Even though I understand all the functions of these two seals, there are still some aspects of the seal that I am not clear on. That will need experiments to be completely clear. I also wonder if the seal can be made even more dangerous. After all, I won't be having someone like Hiruzen to restrict me.
Hmm, now that I think about it, doesn't Orochimaru use his curse seal to seal a part of his soul inside them? I wonder if his seal is just the next step of this seal. That said, even if that is the case, it won't explain how Orochimaru is able to divide his soul to do so. Sigh, that guy is even more weird than Danzo. It'd be so damn helpful if I could read his memories!'
Unfortunately, there was no way that Fujin could think of to make that absurd thought a reality at that moment. He shifted his attention back to the head in front of him as he thought, 'Luckily, there are no backdoor mechanisms for Danzo to know if or when either of the seals get activated. So, he should be in the dark about the fates of these two. Sadly, I can't read their memories to understand his intentions either.
Oh well, it doesn't matter much. I already know what to expect from Danzo, but he doesn't know much about me. Even if Hiruzen gave him all my information, he still wouldn't have the right picture. Regardless, I would need to experiment…'
Fujin let out a sigh and muttered, "It looks like I'll have to leave the village once again in the future after I master this seal and find more bandits and rogue ninjas to experiment. Meeting Shigeki will have to be pushed back until then."
He looked at the seal and thought, 'Though I felt this issue earlier, I didn't focus on it as I was more focused on the workings of the seal. But, how do I apply this seal on a person?
Making a seal imprint shouldn't be an issue. I just need to create the 3 parts for both the seals and then merge them together. But, how do I create an imprint in the seal such that only I can deactivate this seal? Learning how to create that and add it to curse seals will take some time.
Another issue is that I have only studied that seal through the curse seal on this dead Root ninja. So, I am completely in the dark about any limitations this technique might have and the theories behind it. So applying and improving this will be dependent on me.'
Fujin stretched his body and muttered, "Oh well, I'll work on this later. Hopefully, it shouldn't be too difficult. That said, I wonder if I can lift this seal…"
Fujin suddenly had an idea. He pondered it deeply. Soon, the idea took root. Fujin thought, 'It is difficult… Very difficult. I will probably fail. But there is no harm in experimenting. After all, this head is useless to me now. I might even get more insights about how this seal is applied.'
Fujin's eyes glowed as he observed the two seals once again. He analyzed, 'Though the two seals are independent of each other, the second seal will be triggered if anyone attempts to remove the Cursed Tongue Eradication Seal or the second seal. So, the result will be the same as when I tried to read the memories.
I will ignore the Cursed Tongue Eradication Seal. If I manage to neutralize the second seal, then I can remove the Cursed Tongue Eradication Seal later. What I need to do is stop the second seal from getting triggered. How should I proceed?'
Fujin began analyzing his options. The seal would get triggered if it detected a foreign Yin Chakra or if someone tried to remove it forcibly. After planning for a bit, Fujin began inscribing some seals on the head. His plan was to counter Juinjutsu with Juinjutsu. Two Shadow Clones appeared next to him and began helping him out.
The seals he inscribed on the head were to try and stop the seal from destroying the brain. As for the attack, since Fujin wasn't using any Yin chakra, he was under no threat. Fujin had already studied the seal very thoroughly, so he wasn't worried about it harming him.
The head soon became covered in seals. However, since the seals hadn't posed any threat yet, the seal on the back of the Root ninja's head didn't trigger. Once Fujin was ready, he controlled all the seals and attacked the seal on the back of the head.
As he observed, Fujin thought, 'I have two main tasks to do. First, I have to stop the seal from destroying the brain. And secondly, I have to isolate the entire seal, including the imprint Danzo left.'
If Fujin succeeded, then even if he couldn't unseal the seal, the seal would become useless as it wouldn't be able to do its task. It would also allow Fujin to study the seal more closely and understand all its secrets.
Unfortunately, while Fujin's plans were good, they weren't good enough. Fujin managed to keep the brain safe for a few seconds and used that time to isolate the seal. Unfortunately, he failed to do so due to Danzo's imprint and the seal managed to damage the brain. Within a few seconds, the brain was sufficiently damaged to ensure that no memories could be read from it.
Fujin sighed and muttered, "As I thought, this is too difficult. That imprint is pretty much buried into his head. I'll need to experiment on a lot of Root ninjas to have any chance of success. But where would I find so many Root ninjas? Leave it. I had sufficient gains from studying the seal."
Fujin extended his palm towards the head of the Root ninja. Chakra was emitted from his palm and began spinning at a high speed. It was like the Rasengan, but not the usual one. Instead of forming a sphere, the chakra engulfed the head while moving rapidly. Within a few seconds, the head was completely destroyed. The bodies of the two Root ninjas were also destroyed. Danzo would never know where and how his two subordinates died.
With the traces of the two Root ninjas wiped out, Fujin decided, 'It's time to read the memories of that Grand Priest of Jashin.'
Fujin removed his bracer. On his forearm was a storage seal that he had inscribed on his arm. Fujin focused on it and a scroll popped out. It was the scroll that he had stolen from Uchiha Akihiko and kept it hidden since then. A few seconds later, the body of the dead Grand Priest of Jashin lay on top of a stone table.
