Never underestimate Eye Power four or five times greater than that of a Three-Tomoe Sharingan.
Uchiha Mikoto had no Indra's Chakra. If she did, her Eye Power would be several times that of an ordinary Three-Tomoe Sharingan user as soon as she awakened her Three-Tomoe Sharingan.
What Uchiha Mikoto had achieved was already remarkable. At the very least, she now had the foundation needed to awaken the Mangekyō Sharingan.
As for when she would awaken it, Uchiha Yi had no idea. Some people had to witness the death of someone they cared about, while others could awaken the Mangekyō Sharingan after nearly losing a romance. The gap between people was enormous.
Given Uchiha Mikoto's circumstances, Uchiha Yi could not say what kind of shock she would need to awaken the Mangekyō Sharingan.
Of course, another path lay before her: rather than chase the Mangekyō Sharingan blindly, she could focus on Yin-Yang Release. For now, Uchiha Yi had no intention of having her learn Sage Mode.
On that point, Uchiha Yi had to admit that the Senju Clan held a real advantage over the Uchiha Clan.
Take Tsunade and Nawaki. With repeated injections of Nutrient Serum containing Hashirama Cells, their constitutions would improve significantly. Learning Sage Mode afterward would not be especially difficult for them.
For Uchiha Yi, though, the Sharingan and his unstable mental state made mastering Sage Mode anything but easy.
He could not guarantee that even after numerous injections of Nutrient Serum, they would find learning Sage Mode as easy as he had. After all, Uchiha Yi had effectively cheated. It would certainly be much harder for them than for Nawaki and Tsunade.
Once Tsunade and Nawaki had mastered Sage Mode, awakening the Sharingan afterward would not pose much of a problem for them.
In that respect, Tsunade