Naruto endured the intense pain as the nerves slowly connected.
The red Sharingan gradually linked with Naruto's optic nerves.
The darkness in his right eye disappeared, and light returned once again.
His vision became incredibly sharp, and his perception extremely sensitive.
Naruto suddenly felt as if he had entered bullet time.
"No wonder the Uchiha clan's shuriken techniques are so terrifying… With eyes like these, it's basically cheating."
Naruto clicked his tongue as he observed the scene through his right eye.
He casually threw a kunai.
In his vision, the kunai seemed to move extremely slowly, as if time had almost stopped.
Naruto quickly threw another kunai toward the first one.
Clang!
The two kunai collided and flew off to both sides, sticking into the edge of a target.
Naruto frowned slightly.
This was because his suddenly enhanced dynamic vision caused his body to move out of sync with his thoughts.
Something similar had happened when Uchiha Fugaku trained with Shisui in the past.
"Looks like I still need some time to adapt."
Naruto looked at his hand and muttered.
Adapting to the Sharingan was far more difficult for him than for a normal Uchiha.
After all, he only had one eye.
The visual difference between one Sharingan and one normal eye was far more uncomfortable than activating both Sharingan at the same time.
This was also why Kakashi often covered one eye.
Moreover, after transplanting the Sharingan, Naruto's chakra was continuously flowing into it.
Naruto roughly estimated the consumption.
About 1% of his chakra.
"...Not even as fast as my natural recovery..."
As Naruto poured more chakra into the Sharingan,
the three tomoe in his eye began spinning rapidly.
Soon they formed a four-bladed windmill pattern.
Naruto immediately felt the chakra consumption increase by more than ten times.
Even with Naruto's current 10 units of chakra, he could only maintain it for about half an hour.
And after activating the Mangekyō Sharingan, his dynamic vision did not improve further.
Instead, a burning pain slowly began to spread through his eye.
But soon, a different kind of chakra slowly flowed into his eye after the Mangekyō activated.
The burning pain gradually disappeared.
Ashura's Yang chakra!
A special type of chakra that could repair physical damage.
"No wonder Uchiha users start crying blood after using Mangekyō for less than ten minutes."
Without Yang chakra, the damage to the eyes would be almost irreversible.
Naruto didn't know why transplanting a sibling's Mangekyō could prevent this damage.
But the Second Hokage once explained that the Sharingan is born when the brain experiences intense emotional stimulation.
This creates a special type of chakra that affects the optic nerves and changes the eyes.
That is why the Sharingan is called the eye that reflects the heart.
Naruto knew that this chakra was actually Indra's Yin chakra.
Most likely, the special organ connected to the eye could not produce enough Yin chakra to support the Mangekyō Sharingan.
But after transplanting a close relative's Mangekyō and merging the two,
the function of that special organ in the brain would double.
That was why after obtaining the Eternal Mangekyō Sharingan, the eye power increases while the burden on the body becomes smaller.
This also explained why Sasuke and Itachi couldn't simply exchange Mangekyō eyes to awaken the Eternal Mangekyō.
Even though the eyes could be swapped, the special chakra-producing organ existed only once.
Only when the two merged together could the Eternal Mangekyō Sharingan be awakened.
And even then, success wasn't guaranteed.
The closer the blood relationship, the higher the success rate.
Otherwise, the special organ behind the eyes would reject the transplant.
Naruto thought about another example.
Obito.
He simply relied on his powerful Yang chakra from Hashirama's cells to constantly repair the damage caused by Mangekyō.
Naruto's situation was similar.
At this moment,
Naruto clearly felt the ability of Shisui's Mangekyō in his right eye.
He could release a wide golden light, pulling the enemy's mind into a genjutsu space, instantly destroying their consciousness.
At the same time, Naruto excitedly discovered that Shisui's Susanoo had already reached the third stage.
Unfortunately,
even with Naruto's 10 units of chakra, he couldn't release that level of Susanoo.
At best, he could barely control something like the first-stage half-body Susanoo, similar to what Sasuke used against Danzo, and only for a few seconds.
This was most likely because he only had one Mangekyō eye.
After all, Obito had already proven that a single Mangekyō was weaker than having two.
It also consumed far more chakra.
Naruto could clearly feel that activating Susanoo with one eye required an extremely terrifying amount of chakra.
Even so,
the benefits the Sharingan gave him far exceeded his expectations.
From now on,
this would be the period where he truly accumulated strength.
Naruto was so excited that he couldn't sleep the entire night.
The next morning,
when the alarm clock rang loudly,
Naruto quickly put on an eyepatch over his right eye.
Then he immediately began his taijutsu training for the new day.
"Let's test Might Guy's Strong Fist first."