Prologue
A dark figure approaches an ancient altar. His visage old and weary, the man limped slowly but surely, his face unreadable. The man's walking cane was the only source of sound in the dark ruin, not even the sound of insects can be heard deep inside the place. When he finally arrives at the altar, the man paused and he lets a small smile come to his face.
"Finally after all these years of fruitless searching I have found you" the man hoarsely said. The smile on his face haven't changed and despite himself tears of joy flowed from his one remaining eye. A large scroll lies in the middle of the altar. The scroll itself is ancient, evident from the fragile state it is in as well as the dirty yellow paper that it held. Golden ornaments adorned the scroll, but they too were ravaged by time.
"With this I can finally set right what went wrong and secure the future that I want"
As he said that the elderly man unseals the scroll and lay it on the altar, even as he does a complicated set of hand seals. When he's done the scroll flashes white and in that instant the man was gone from this world like he never existed.
An incredible sensation filled his entire body and Uchiha Sasuke instantly felt better than he has ever since the day where he lost everything. He can barely see himself, a specter floating aimlessly in the world. He turned around seeing the entrance to the ruin and surrounding it was the corpse of multiple demons that he had slain to get to the scroll. The battle had raged for an entire week but he had finally emerge victorious against the 100.000 demons guarding the ruin. It would have been faster if he had been younger and still fully armed. As it were, he had lost his left eye which he sacrificed for Izanagi to survive the battle against Madara, the Ten-Tails jinchuriki years ago. Without his left eye from which his Amaterasu originated he had also lost use of Susanoo which requires both Mangekyo Sharingan to use. The fact that he was now a frail old man simply makes matter worst. The stronger demons were nigh-immune to genjutsu so he had been forced to waste a lot of chakra to use Tsukuyomi to make the more numerous weaker demons to kill themselves so that he can better focus on the remaining stronger foes.
His ghastly form floats away from the ruins and into Konoha. The once prosperous ninja village is now but a shell of its former self. Only a small number of shinobi can be spotted and the civilians fearfully went through their insignificant daily life. The Hokage monuments now sport six faces but Sasuke's gaze only ever bother to look at the most recent face carved into the mountain. Before he can further think about his "friend", a black-white vortex swirls vigorously in the air drawing his ethereal form in.
'Yes, it's working. I can finally claim the path that I want. With this I shall save everyone dear to me. Itachi, mother, father, and the rest of the clan, just you wait I will save you all!'
With those thoughts in his mind, the last Uchiha journeys to the center of the vortex and as he did so, his form vanish without a trace. His goals are clear to him, and as long as he gets what he want then he doesn't care about anything else.