Itachi Uchiha's Impure World Reincarnation this time served three purposes:
First, he acted as a guide, leading everyone into Ame-no-Futodama-no-Mikoto's trap and leaving them stranded on the moon.
Second, he betrayed his allies and left without a word, successfully allowing Android 18 to stab the White Snake Sage, freeing Madara Uchiha from Isshiki's restraints, severing the God Tree, and laying the groundwork for the appearance of the "pen."
Third, he guided Sasuke to Lin Qing, who was lying in the desert.
However, its greatest and most important significance... Lin Qing looked at Sasuke as he slowly sheathed his blade. His eyes were closed, his expression calm, as though he had merely done something insignificant, but...
A tear slid from the corner of Sasuke's eye.
He wanted to hold back his tears, but then he heard Lin Qing say, "If you want to cry, then cry. He... was your brother, after all."
Sasuke met Lin Qing's gaze.
He understood what Lin Qing meant.
He was not grieving because of the blood ties of a "brother." Rather, in the distant past, before Itachi became the Itachi Uchiha he was now, he truly had been an outstanding older brother, the eldest son his parents were proud of, and a clansman praised by all.
Itachi Uchiha later became a beast who slaughtered his entire clan. That was true.
But before he became that beast, he truly had been the most important family member in Sasuke's life.
He was not mourning Itachi's death.
He was mourning those beautiful memories of the past, memories that could never return.
Perhaps...
Lin Qing watched Sasuke silently shed tears in the rain.
"Dying by Sasuke's hand was the greatest meaning of Itachi Uchiha's return through Impure World Reincarnation this time, wasn't it?"
Sniff—
Sasuke sucked all his snot back