Uchiha Shunichi used his Sharingan's Genjutsu to take control of her, then made her perform One's Own Life Reincarnation.
This forbidden technique, which came from Chiyo, could not only revive someone who had recently died, but also heal a gravely wounded shinobi.
After all, the essence of this forbidden technique was to give one's own life force to another person. Its healing and resurrection effects were merely by-products.
Back when Uchiha Shunichi had been considering ways to resurrect people, he had kept thinking about making someone else perform a resurrection technique.
After all, even though he possessed the Dōjutsu Regression, using it for someone else's sake would be a bit too wasteful.
Besides, late in the Naruto story, Uchiha Madara had controlled Uchiha Obito to resurrect himself. So, in principle, there was nothing wrong with making someone else perform a resurrection technique.
Still, Uchiha Shunichi had never tried it before, so he felt somewhat apprehensive.
Things went unexpectedly smoothly. The slightly older female medical shinobi walked over to Mei Terumi and performed One's Own Life Reincarnation without any trouble.
Even though she had never learned this Ninjutsu, she still managed to perform it smoothly under the control of Uchiha Shunichi's ocular power.
As life force flowed into Mei Terumi, the horrific wounds on her body began to heal at a visible rate, and her somewhat unruly chakra gradually settled down.
Just then, however, the female medical shinobi's chakra suddenly ran low, leaving her unable to continue healing Mei Terumi's wounds.
Just as Uchiha Shunichi was about to give her some of his own chakra, the other medical shinobi took the initiative and channeled theirs into her.
With that, the situation stabilized again.
Soon, Mei Terumi was out of mortal danger, and most of her wounds had healed, including the skin