Just as Naruto Uzumaki and Karin Uzumaki met, Shin Uchiha also said goodbye to Shisui Uchiha.
Some things could no longer wait. He had to bring Princess Tsunade back. Whether it was for Mikoto or Uchiha Itachi, he needed to recall Tsunade, one of the finest medical experts in the shinobi world.
Even her Hemophobia would not be a problem. The Uchiha Clan had plenty of genjutsu experts, and a simple hypnotic suggestion should more or less eliminate it. As for why Tsunade had never sought a permanent cure all these years, she probably harbored some regret or had experienced something deeply disappointing that made her choose to run away. That was why her Hemophobia had persisted.
Besides, there was still no news about the second stage of the Kumogakure Raikage's secret technique, Lightning Release Armor. Shin Uchiha did not want Konoha's spies risking their lives on his account, so he planned to wait a few days until Kōrei Uzumaki recovered, then copy a nearly perfect Uzumaki Clan bloodline from the three surviving members. After that, he would go to Kumogakure and meet the Fourth Raikage.
Since the second stage of Lightning Release Armor was difficult to obtain, he would go straight to the Fourth Raikage and copy his fully mastered Lightning Release Armor. By then, he would already possess an incomplete sage body and the physique granted by the Uzumaki Clan's bloodline. He should be able to skip the second stage entirely and train in the fully mastered version.
Of course, some physical suffering would probably be unavoidable. Still, to be on the safe side, Shin Uchiha felt he should bring Tsunade back. With her watching over him or lending a hand while he trained in Lightning Release Armor, he could progress faster and spare himself some pain.
So,