Yamato's words did not pull Kakashi out of his despair. Ao's words had dealt him far too great a blow. Kakashi had not believed Ao at first, but after carefully thinking it over, he felt it was very likely true.
Obito's obsession with Rin had been incredibly deep. Kakashi had seen him more than once secretly staring blankly at Rin's photograph, even moving his lips at times...
If that shout back then had truly come from Obito, then everything made sense. For some unknown reason, Obito had survived, and when he came looking for Kakashi and Rin, he happened to witness Rin's death.
Under those circumstances, Obito had coincidentally awakened the Mangekyō Sharingan, greatly increasing his strength. He had successfully dealt with those enemies, then gone alone to Kirigakure, used his Mangekyō Sharingan to control the Fourth Mizukage, and launched a large-scale purge of Kirigakure's ninjas.
"The only flaw in this deduction is the condition for awakening the Mangekyō Sharingan. If I knew that condition, perhaps every mystery would be solved!"
After lying sprawled on the ground for a long time, Kakashi endured the pain and shakily climbed to his feet. He headed toward the place where the three were training. Although Obito's matter had left him somewhat despondent, Kakashi still knew his duty. If he completely fell apart, whether those three kids could survive would become a question.
As for Obito, he would continue investigating after this mission was over.
Enduring the pain, Kakashi slowly arrived at the training grounds. With Sasuke's absolute superiority in strength, Naruto was once again lying on the ground bruised and battered, while Sakura was once again being treated by Sasuke. The gap in their strength was simply too great.
"Kakashi-sensei, what happened to you?" Sakura, who was receiving treatment from Sasuke's Mystical Palm