Akechi would find that lthere was little effort actually involved in entering the door; he simply required to show the intent to go through and the passage, an impassable gate to the various manifestations of Sawako's mind, easily fell apart at his touch. The dark fibers unwound from their tight coil and fell apart, and the door itself blew away in shards as if it were little more than dust in the wind.
While every room and memory up to now had been painted in Sawako's colors, what lied beyond that door was darkness. No room. No hallway. No light. Just darkness. While one might be quick to dismiss this as a void, make no mistake; this abyss was far from "empty". The blackness itself had weight, as if painted by physical shadows. If this made no sense, it was because Sawako's mind made no sense to herself.
Furthermore; the room Akechi had been in previously, as well as each colorful incarnation of Sawako's mentality, vanished in the same disintegrating manner the door had gone. While Akechi himself may not have moved, the area around him was nonetheless different. He may have felt as if her were floating. Or falling. Or standing. Hell, maybe all three at once.
Unlike before, he was not being "shown" memories; He was "living" them. For all intents and purposes, Akechi was Sawako throughout these memories. Within her mind, he would feel as she had. He would see as she had. He would experience as she had. No filters, no diluted secondhand experience.
His name was "Ashuri". A name that had been long forgotten, and yet belonged to someone he would no longer ever be.
His name was "Kuroyuki". A name that had been forgotten, and yet belonged to someone he would inevitably become.
He would see a mother and father, the joy of telling them about having passed the test to become a Genin.
....And the pain of knowing that they were lost years, upon years ago. They joy of remembering he had warm, loving parents...and the hard realization of them being "gone".
He would see a beautiful youkai, a demoness of great strength, whom he was attracted to and yearned for nothing other than their affection.
...Andthe pain, the sorrow of losing them.
He would see a close group a children; eagerly discussing ways to become genin. Looking up upon Akechi as if he were one of their leaders. And then, that same group graduating from their first exam, becoming shinobi of the Stone Village. The pride. The joy.
....And then the pain of having his friends turn upon him, and in turn turning against them. Of having his mind pushed well beyond the breaking point.
He would see a group of powerful youkai, of which he was one, and feel betrayed over their lack of care over losing one of their own, the one he had loved.
He would feel the pain of having his body torn apart and regrown, rebuilt, into something inhumane. He'd feel the pain of having his head severed, held to face his limp body, until the fibers in his neck managed to reconnect and sew both parts of himself back into place some time later.
He would have firsthand experience of the unbearable hunger that rotted away his flesh and muscle, exposing the shrunken dark fibers within. How, even without a limb or a head, his life itself could continue in painfully cruel, unfair ways.
...The pleasing, saving grace of sinking his teeth into the decayed flesh of those who had been his friends, the same friends that had attacked and been attacked by himself. How each bite eased the pain in his own body, each taste surpassing any possible Pocky or Dumplings. This taste was to die for.
He would become a rebel, turning his back to his companions, to pursue his own guest of anger and revenge.
He would have horrific revelations that he had murdered his friends to ease her own pain and suffering, only to find it replaced with apathy and anguish. The pain of being unable to end his own life, because his body was simply too durable.
He would feel the wrath, the scorn, of failing, losing his physicasl body and being bound for decades upon decades, over a century, with only temporary freedom gained through human vessels.
...He would feel the desperate attempts at finding any way of escaping the pain, welcoming anyone...or anything that would protect him from further pain.
...He would feel the joy of having a a new vessel, a new physical body, that could withstand the corrupting chakra of his spirit. A body he could gradually merge his consciousness with, overwritting the painful memories of his host and assimilating them into his own as he had done many times in the past.
...It was not one set of memories hidden behind the door; but two. Neither were fake. Both were real. And, their simultaneous existence and being experienced at once would no doubt be quite painful. The process itself may have taken anywhere from seconds, to hours, or even days to Akechi; but the memories he had been given access to were not gentle with him in the slightest, and could easily have caused mental overload, or worse, if he dropped his guard. The weight shadows of the black realm? All subconscious mental attempts at breaking his will, overwriting them with her own. It wasn't intentional, of course.
At the end, when Akechi's mind regained itself after living through memories that were not his own, he would find himself seated at a floating table, sailing amidst a sea of blackness, with two new Sawako's for company; Sawa-Black and Sawa-Red. Both wearing the same dress Akechi had initially met her in, albeit of their own respective colors.
"Never did I expect someone to dive into the mind of a small girl in search of her memories. Very admirable, Akechi-san." The first one spoke, the black one, acknowledging Akechi's presence. "Now that you have found them and know them for what they are...Do you still wish to return them to her? To us? To take away my bright-colored fantasy and replace it with the dark of the past?" Sawa-black spoke, leaning against the unresponsive Sawa-red. "....." The expression on the red-dressed girl's face mirrored the one on her face in the real, physical world. The mesmerized gaze...
"Welcome to my mind, Akechi-san." "...Please...don't....hate me...." "You are our precious guest."
[Marked]
*Pull* *Pull* *Pull* 
