The history of preserving the Sharingan of deceased clansmen can be traced back to the period when the Uchiha clan abused the forbidden technique 'Izanagi'.
Although the clan banned that forbidden technique, they still kept the method of preserving eyes. Despite the clan spending considerable financial and material resources on this every year, several elders never reduced this expense.
This is because the Sharingan, as a special Kekkei Genkai, has great compatibility with direct blood relatives. During battles between ninjas, there is no guarantee when someone might lose their eyes.
At such times, if your deceased blood relative had a pair of Sharingan preserved by the clan, a simple transplant would suffice. The spare eyes could restore your vision in no time, and the pupil power contained within might even surpass the original.
This is also the main reason why the clan strives to preserve the Sharingan.
Given Uchiha Ryun's current status, as long as he needs it, there is no reason for the clan to stop him from retrieving his deceased father's Two Tomoe Sharingan.
"Please help me verify this when you return, Great Elder. If possible, I will go to the clan territory in the next few days to retrieve my father's eyes."
Ryun looked seriously at the Uchiha First Elder.
"It is possible, but are you sure you really want to take the eyes just to keep them as a memento? Preserving eyes requires a very strict cold storage environment. If they are taken out and not stored properly, they will spoil in just a few days."
The Uchiha First Elder rarely gave such a reminder.
Hearing this, Ryun fell silent, a thoughtful expression on his face as he pondered something.
In truth, after obtaining the eyes, he would not consider the storage issue. What he was thinking about was how to completely merge the two pairs of eyes into one.
In the original story, the Eternal Mangekyō Sharingan is awakened by transplanting another pair of Mangekyō Sharingan from a direct blood relative.
But the original story's use of the word 'transplant' is problematic. If simply exchanging two pairs of eyes could evolve them into the Eternal Mangekyō, then characters like Uchiha Itachi and Uchiha Izuna wouldn't have needed to die. They could have just swapped eyes, resulting in two pairs of Eternal Mangekyō.
There is also no record of the Uchiha clan ever having two pairs of Eternal Mangekyō Sharingan in any era.
The setting of the Eternal Mangekyō Sharingan is that two pairs of eyes merge into one, becoming a single entity for one person. This setting aligns with the original story.
How to merge two pairs of eyes into one? First, we can rule out the absurd idea of squeezing two pairs of large eyes into the same eye sockets.
After eliminating these two incorrect assumptions, it proves that the use of the word 'transplant' itself is wrong.
The only remaining explanation for merging two pairs of eyes into one is the fusion of pupil power.
As a member of the Uchiha clan, Ryun can clearly sense the existence of pupil power. Even without the Mangekyō Sharingan, the Three Tomoe Sharingan contains abundant pupil power.
This is a power distinct from chakra. The essence of pupil power is Yin Release.
Only by fusing the pupil power of two Mangekyō Sharingan can the curse of blindness from overusing ocular techniques be broken, as well as the physical burden of using such techniques, achieving the Eternal Mangekyō Sharingan.
Ryun currently does not know how to extract pupil power from the Sharingan, which is why the Uchiha First Elder's reminder made him silent.
What he really wants is to extract the pupil power from his father's eyes and absorb it into himself. He doesn't expect to break the bloodline 'restriction' and awaken the Eternal Mangekyō, but at least it could help his eyes advance further, possibly awakening an ordinary Mangekyō.
This is not wishful thinking or baseless speculation. There is a reasonable basis for it.
Ryun possesses both Uchiha and Senju bloodlines, along with another pair of Sharingan from a direct blood relative. He has already gathered a significant part of the 'puzzle' of the Sage of Six Paths' power. Yet, all he hopes for is to awaken a simple Mangekyō Sharingan.
This request is not excessive and has a high probability of success.
Ryun often likes to ponder things in his free time. His desire for the Mangekyō Sharingan led him to think of this method.
He also has another way to evolve the Three Tomoe Sharingan, which is equally scientific and reasonable with a high success rate. However, that method is too difficult for now, so he decided to request his father's eyes in hopes of successfully awakening his own.
This is the simplest method and the easiest to accomplish.
"The Great Elder is right. I didn't consider this properly. Then I'll leave my father's eyes with the clan for now. I'll retrieve them once I've prepared the cold storage equipment."
Ryun thought that once he reached the Wind-Fire battlefield, he would see if any unfortunate clansmen died in battle. He could then borrow a Sharingan to experiment with absorbing pupil power. Once he successfully develops this 'technique', he would retrieve his dead father, Uchiha Mori's eyes.
"Very well. Taking the eyes of a deceased relative is not a problem. You can decide when to retrieve them."
The Uchiha First Elder gave Ryun some reassurance.
Since the eyes are in someone else's possession, Ryun was worried they might not hand them over. But after hearing the Great Elder's words, he felt more at ease.
After seeing off the Uchiha First Elder, Ryun sat alone in the quiet room, performing his daily maintenance and stabilization of the Dragon Pearl in his body to ensure its properties remained intact.
In the future, the conversion of natural energy into Senjutsu Chakra would rely on it. This step required long-term effort. Even after mastering Sage Mode, he would need to regularly nurture and maintain the Dragon Pearl in his body.
The next morning.
A special envoy group from Kumogakure finally arrived in Konoha.
Sarutobi Hiruzen immediately met with the envoys and showed great importance to the visitors and the relationship between the two nations.
After all, on the surface, the Kumo-nin came with the peaceful intention of forming an alliance. The Konoha higher-ups saw this as a gesture of goodwill and respect, so the entire village treated the group with great courtesy.
At this time, the Kumo envoy group showed no hostility, as if they were truly sincere in coming to Konoha to form an alliance and jointly resist Iwagakure.
But within Konoha, one person viewed this Kumo envoy group with suspicion and even harbored a sharp killing intent.
This person was Uchiha Ryun.
As a transmigrator familiar with the original story, Ryun knew exactly what Kumogakure was like.
In the original story, the Kumo envoy group came to Konoha only twice.
The first time, they kidnapped Kushina, the intended Nine-Tails jinchūriki. The second time, they went even further, daring to enter the Hyūga clan's territory to abduct the young Hinata.
They were more lawless and arrogant than bandits. Faced with these bullies, the weak and incompetent Konoha higher-ups chose to yield again and again.
As Kushina's recognized boyfriend, Ryun would not allow these Kumo scum to act recklessly. If they dared to target his 'little tomato' as in the original story, Ryun would ensure they died horribly.