At this time, Yosuke and his group appeared in the Land of Mountains.
The Land of Mountains lies to the west of the Land of Birds, surrounded on all sides by towering peaks and dense forests.
Deep within the mountains at the center of the Land of Mountains lay the ruins of a village.
This village was called Yōne Village.
During the Second Great Ninja War, Yōne Village fought against Konohagakure. In the beginning, it was able to hold its own against Konoha. However, after its main forces left the village, it was ambushed by Konoha, resulting in a drastic loss of strength.
During the conflict, the village chief was killed in an accident. The new village chief subsequently signed a ceasefire agreement with Konoha. Not long after, Yōne Village was ambushed and completely annihilated by Takigakure ninja.
Thirty years had passed since the village's destruction. The ruins were now covered in thick moss and had become a paradise for wild animals.
When Itachi had seen the intelligence reports on the Land of Mountains and Yōne Village back in Konoha, he had already decided to choose this place as the new refuge for the Uchiha clan.
The location of Yōne Village was secluded, and the surrounding area was rarely visited by people—making it an ideal settlement for the Uchiha clan in their current situation.
Sasuke tugged on Itachi's hand and asked,
"Brother, are we going to live here from now on?"
Itachi gently rubbed Sasuke's head. Though the place looked desolate, in Itachi's eyes, it represented hope.
"Yes. From now on, this will be the new home of the Uchiha clan."
Now serving as clan head, Itachi took on his responsibilities and directed everyone in rebuilding the settlement.
Night fell.
The Uchiha clan members rested inside makeshift shelters they had hastily constructed.
Meanwhile, Yosuke approached Itachi and said,
"Come with me."
Itachi followed Yosuke to a secluded area.
Yosuke asked solemnly,
"When did it start?"
"Master?" Itachi was confused by the sudden question.
"During the battle in Konoha, something was clearly wrong with your body. Even accounting for the severe side effects of the Mangekyō Sharingan, this isn't the condition of a ninja who hasn't even reached their prime yet. How long were you planning to hide this from me?"
Itachi lowered his head apologetically.
"I'm sorry, Master. I didn't mean to hide it. But at the time, the situation didn't allow for any mistakes on my part."
Yosuke didn't respond. Instead, he placed his hand on Itachi's forehead and began sensing his physical condition.
Moments later, Yosuke withdrew his hand. His expression, once merely serious, turned angry.
"When the Nine-Tails incident ended and before I left Konoha, what did I tell you? If you encountered any problem you couldn't resolve, you were to come to me. Do you have any idea what state your body is in right now? Calling it 'in shambles' would be putting it kindly!"
From what Yosuke sensed, Itachi's condition was abysmal. His vital organs had already begun to deteriorate—truly horrifying to behold. Continued use of the Mangekyō Sharingan would only accelerate the degeneration until it became completely irreversible.
Yosuke asked internally,
"System, if someone I grant my blood to can learn my abilities, will they also receive my other traits?"
[Humans transformed by the host's blood no longer possess immortality, but all other characteristics of the host's blood remain intact.]
Yosuke let out a sigh of relief. The anger on his face eased.
As long as the powerful regenerative trait remained, Itachi could still be saved.
Yosuke scolded him,
"You really don't give your master any peace of mind. An individual's strength is always limited—don't try to shoulder everything alone."
Itachi lowered his head in shame.
"Have you fully mastered all forms of Sun Breathing?" Yosuke asked.
Itachi nodded.
"Yes. But I'm still not proficient with the forms beyond the Eighth."
"That's good enough. I originally planned to do this after you reached your peak, but given your current condition, we have to advance the plan."
Yosuke used the Ame-no-Murakumo Sword to cut open his wrist. Blood poured from the wound without stopping—but instead of dripping to the ground, it floated in the air.
"Swallow my blood. It will grant you powerful physical abilities and regeneration, cure your illness, and allow you to learn my abilities."
Trusting Yosuke completely, Itachi swallowed the blood without hesitation.
The Demon King's blood entered Itachi's body and immediately began reconstructing him.
Having lost its immortality trait, the Demon King's blood did not alter Itachi's appearance. However, a faint aura of a demon gradually emanated from his body.
Ever since falling ill, Itachi had felt as though his body was bound by invisible shackles. After being transformed by Yosuke's blood, it felt as though those shackles had been removed—his body suddenly felt light and free.
Even more astonishingly, his eyesight—which had noticeably deteriorated due to the use of the Mangekyō Sharingan—had begun to recover.
The regenerative power of Yosuke's Demon King blood was no weaker than that of Hashirama Senju's cells.
If Hashirama's cells could prevent Obito's Mangekyō Sharingan from going blind, then Itachi—transformed by Yosuke's blood—would no longer face blindness either.
Itachi had already obtained Fugaku Uchiha's Mangekyō Sharingan. Originally, he had no intention of transplanting them himself, planning instead to reserve them for Sasuke in the future so he could awaken the Eternal Mangekyō Sharingan.
Now that he would no longer go blind from using the Mangekyō Sharingan, Itachi was filled with joy.
"Itachi, catch."
Yosuke tossed the Ame-no-Murakumo Sword to him.
"I've seen that black flame you use. Ordinary blades can't withstand its heat. This sword should be able to endure your black flames. I'm giving it to you."
"Master, then what about you?" Itachi asked.
Yosuke waved his hand indifferently.
"The Ame-no-Murakumo Sword is just icing on the cake for me. It doesn't affect my actual strength."
Feeling Yosuke's concern, Itachi clenched the sword tightly in his hand.
"Yes, Master!"
Over the next month, Yosuke and Karin also helped the Uchiha clan build their new home—everyone except Deidara.
Yosuke also taught Itachi the forms of Blood Breathing. However, Itachi unexpectedly developed his own Blood Demon Art.
But Itachi's Blood Demon Art was not a pure one. It existed somewhere between Blood Demon Art and genjutsu—it could spread through sound, drawing targets into a dreamscape woven by Itachi without them realizing it. However, it could still be dispelled in the same way as genjutsu.
Now, Itachi's genjutsu was no longer limited to visual contact or hand movements—it could also be transmitted through sound, making it nearly impossible to guard against.
Meanwhile, Yosuke was also learning.
Itachi was teaching Yosuke the Uchiha clan's Fire Release ninjutsu.
"Master, that's not the hand seal for Fire Release—that's Lightning Release…"
"Huh? Isn't it?" Yosuke asked.
He clumsily began forming the seals again.
"Master… the seals are right this time, but the order is wrong again…"