Uchiha Yi's sensory abilities were far superior to those of ordinary people, so naturally, he could tell that Mito Uzumaki was nearing the end of her life. Had she not become the Nine-Tails Jinchuriki, she probably could have lived for another ten years or more.
After all, Utatane Koharu and Mitokado Homura were both still alive during Boruto: Naruto Next Generations, and they could still come out and boss everyone around.
Mito Uzumaki had fought on the battlefield, unlike Utatane Koharu and Mitokado Homura, who enjoyed good food and drink. Since the end of the First Shinobi World War, neither of them had returned to the battlefield. Forget improving their strength—it was already impressive if they managed to keep it from declining.
As the Nine-Tails Jinchuriki, Mito Uzumaki constantly had to expend enormous amounts of chakra to suppress the Nine-Tails, which had caused her health to deteriorate steadily. Otherwise, with the Uzumaki Clan's natural longevity, she would never have ended up like this.
"You're back!" Mito Uzumaki greeted Uchiha Yi warmly, seemingly unaware of his complicated feelings.
"Yes, I'm back, Grandma Mito!" Uchiha Yi brought Kushina Uzumaki over and sat down near Mito Uzumaki. Minato Namikaze, Uchiha Mikoto, and Hyuga Rinka were not there. He did not need to think about it to know they had all gone home.
Coming to greet Mito Uzumaki had been enough.
Ultimately, Nawaki and Kushina Uzumaki were Mito Uzumaki's family. Uchiha Yi could count as something of a family member too, but the others were different.
Those boundaries still needed to be respected.
"Sit down. It seems your strength has grown again since we last met." Mito Uzumaki quietly sensed Uchiha Yi's aura and was shocked to discover that his bearing had undergone another tremendous change. In that respect, he was much like Nawaki