It took Shinji a long time to barely calm the woman down.
Not only had her body been ravaged, but her mind was also on the verge of collapse. Her only remaining emotional anchor was the set of clothes she clutched tightly in her arms—the clothes that belonged to Karin.
So Shinji could not provoke her too much right now. Otherwise, it would likely have the opposite effect.
Once the woman's emotions had settled somewhat, he quietly activated his Mangekyō Sharingan and put her to sleep.
"Ah..."
He sighed.
Given her current physical condition, she would never last until Karin completed her mission and returned to Kusagakure. That alone showed that the grass ninja had never regarded Karin and her mother as one of their own, nor had they ever intended to let them live.
Kusagakure had clearly made up its mind to use Karin's mother to force Karin into completing the mission. Once Karin successfully stole back the Nine-Tails, they would take the Nine-Tails from her body and quietly dispose of Karin, the Jinchuriki who had defected from Konoha.
That way, they could not only obtain the Nine-Tails with ease, but also avoid a direct conflict with Konoha.
Their only loss would be two women from out of town.
Shinji dearly wanted to activate Susanoo right then and wreak havoc in Kusagakure, killing those vermin until the place was turned upside down.
But he knew that if he did that, the consequences would likely spiral beyond his control.
Once the matter blew up and Karin's identity as a Kusagakure spy was exposed, it was hard to say what would happen to her. After all, she had once been coerced into helping the grass ninja assassinate Naruto.
As long as her identity was exposed, Konoha could easily uncover that matter.