Reintegration....

Kakashi suddenly opened his eyes, as he took in a sharp breath. He coughed for a bit, before taking in his surroundings. He was in his old apartment, the one that was destroyed when Pain attacked.

'Never thought I'd see this place again.' he thought fondly.

He got up from his bed, pushing his shuriken bed-sheets aside. He went over to the desk on the side and observed it's contents. There was a bulletin board above the desk, covered in sticky notes with all of his duties. On the desk was a picture of his old team. Kakashi looked at it with regret.

"Never again." he murmured.

He walked out of the room his bare feet plodding on the floor softly. He entered the bathroom and locked the door behind him. Kakashi looked into the mirror and observed himself. He lightly traced the scar on his left eye. After checking for anyone's chakra, he took off his face mask.

Kakashi's face was fully revealed to the mirror. He smirked before concentrating. He closed his eyes before suddenly opening them. Red bled into the eyes as three tomoe suddenly spun into existence. With a pulse of Chakra, he activated the Sharingan.

"Well thanks to the Sage, I can barely feel any of my Chakra being drained. That's good. Now let's go further."

Kakashi pushed more Chakra into his eyes as they morphed. His regular Sharingan turned into a red pinwheel triangle on a black background. (https://www.uihere.com/free-cliparts/sharingan-deviantart-rai-uchiha-sharingan-3228842)

Kakashi felt his Chakra take a hit, but he could manage. He turned to one of his extra tooth-brushes and concentrated. Kakashi felt a tingle in his left eye, as one of the spare tooth-brushes began to be sucked up into a swirling vortex before it disappeared. His Chakra spiked downwards.

To conserve his Chakra, Kakashi stopped flowing Chakra to the eyes. They immediately reverted to his normal grey-black eye color. Kakashi took light breaths before steadying. He looked at the time.

"I should get dressed."

Kakashi stripped his clothes and went into the shower. He turned the handle and waited. The steaming water impacted his skin as he fell into a contemplative silence. He began to think about his mission.

'Okay, I know I can't keep this to myself, that would be too much of a burden on me. But who could I share it too? Not my team, that'd just be stupid. But no one in the village is secure except.... wait of course! Hokage-sama! If he knew what was to come, then we both could plan. I should also inform Jiraiya-sama, but I have to wait until the Chunin exams. I'll have to tell him now though.'

Kakashi quickly grabbed the soap and lathered himself. He washed his body before grabbing the shampoo taking a dollop and lathering his hair. He washed it and stepped out of the shower. Quickly drying his body and hair with a towel, he threw it on the rack before putting on his clothes.

Kakashi put on baggy dark blue pants and his dark blue long-sleeved shirt with the face mask attached. He slipped into his black Ninja sandals before putting on his forest green sleeveless flack jacket. He zipped the jacket closed, as he picked up his ninja headband. He put it on his forehead straight, exposing both of his eyes. He applied a light Genjutsu on his eye.

'I've been known for covering this eye, so it'd be weird if I suddenly exposed it.'

He made it look like his forehead protector was still slanted over his left eye. With that all done, Kakashi went out of the apartment and locked it. He then body flickered away, with no hand signs.

....

Kakashi then reappeared, in a burst of high movement speed, in front of the Hokage tower. He went inside, the guards nodding to him as he did so. Kakashi scaled the steps of the building before walking into a room. A female receptionist was there looking at her papers. She noticed him and let him pass.

Kakashi went up to the door behind her and gently rapped the door. A few seconds later an elderly voice signaled him to enter. Kakashi opened the door and walked inside. Closing the door behind him, he turned around to face the Hokage.

"Kakashi-kun, what brings you here?" the 3rd inquired.

"Hokage-sama, please send away your ANBU guard. I am here to discuss a matter of importance and secrecy."

Now Hiruzen became curious. If it was someone other than Kakashi, he would have denied the request, but he was curious. He made a quick signal, as Kakashi felt 4 signatures flicker away.

Hiruzen gathered Chakra into his hand and slammed it into the ground. Lines of ink erupted from the ground, spanning across the whole room, before disappearing. There was a low humming sound radiating from the room.

"There now, we are properly alone. With my Silence Seal, no one can hear us talk. Now speak Kakashi-kun."

'Hokage-sama, I'm not going to speak, I'm going to show you something." he said, much to the elder Hokage's confusion.

Kakashi braced himself as he gathered Chakra into his eyes. He stared at the 3rd. Much to Hiruzen's shock, a Sharingan appeared in Kakashi's 'right' eye, before further evolving.

"Mangekyo..." Hiruzen murmured in shock.

Kakashi stared at Hiruzen as his right eye tingled. He said one thing.

"Tsukuyomi!"

A bird outside the room began to fly, and just finished the first flap of its wings when Kakashi announced this.

....

The room around them inverted as outside the room, the sky became red and the land black. The sun in the sky turned into a glowing red moon with the three tomoe Sharingan symbol. Hiruzen looked on in shock.

"What the hell..." he stammered.

Hiruzen looked to Kakashi, who was standing there as if nothing was wrong.

"Hokage-sama, don't talk, just watch."

Then with a wave of his hand, images started to play. The next 4 years in Kakashi's point of view were shown to Hiruzen. He saw many things.

The formation of Team 7.

The missions they took.

The Chunin exams.

His funeral.

Kakashi fighting Itachi and Kisame.

Tsunade becoming the 5th Hokage.

The next 3 years passing.

Naruto's return with Jiraiya.

Sakura and Naruto fighting Kakashi.

The Kazekage retrieval mission.

Asuma's death.

Kakashi and Team 10 vs Hidan and Kakuzu.

Pain's attack on the leaf.

Kakashi's revival.

The new of Danzo's death and Kakashi fighting Sasuke.

The 4th Ninja World War.

The Shinobi Alliance.

Obito's reveal.

Madara.

Guy using the 8 gates.

Sasuke and Naruto's new powers.

The Infinite Tsukuyomi.

Kakashi getting his eye ripped out and receiving a new one.

Kaguya.

Team 7's death.

And Kakashi's talk with the Sage.

All of this information in two seconds I real-time. Hiruzen gripped his head in as he felt all this information register within his brain. And due to his eidetic memory, Hiruzen would not miss anything he saw.

Kakashi felt his Chakra levels strike an all-time low after using Tsukuyomi once. He immediately deactivated his Mangekyou as the illusion faded. The skies turned to their regular blue and the sun replaced the Sharingan moon. The deep black ground outside turned into a vibrant mix of brown and blues and time began to flow normally.

....

Outside the room, the bird just started its second wing flap.

Kakashi fell to his knees with his hands on the ground. He felt like vomiting as his forehead became riddled with sweat. His whole body quaked in exhaustion.

'That was only 30 hours in total inside my Tsukuyomi! How could Itachi do it for 73!' Kakashi thought in wonder.

"Kakashi..... what was that?!" Hiruzen barked out. If this was some sort of prank, he would have Kakash demoted to Genin immediately!

"Hokage-sama, trust me, everything you had just seen was real. What you had just seen was the future, from my perspective."

"Hmph, then tell me! What was the real reason the Uchiha clan was exterminated!" the 3rd asked Kakashi.

"Hokage-sama, the Uchiha clan massacre was a result of the Uchiha clan planning a coup after years of feeling isolated by the village after the 2nd Hokage's rule. This isolation was only intensified after the 9 tail's attack when it was reported that an Uchiha released the Kyuubi into the village, and fought Minato-sensei. To prevent this coup, Shisui Uchiha pleaded to you and the other 3 elders of the village to stop the attack with his Mangekyou Sharingan Genjutsu Kotoamatsukami. But soon after you issued the okay with the order, Shisui committed suicide, unable to bear the burdens of killing his clan. Thus the burden fell on to Itachi who killed the whole Uchiha clan and joined the S-rank organization of the Akatsuki as a spy, only under the condition that you spare his little brother Sasuke."

Hiruzen fell silent, before speaking in a weary voice.

"Alright, I accept that you are from the fu-"

Kakashi interrupted him.

"Hokage-sama, I'm not done. You only know that part, but you don't the darker truth of the Uchiha massacre. Shisui did commit suicide, but not for the reasons you know. On his way to use Kotoamatsukami on Fugaku, the head of the Uchiha clan, he was confronted by Elder Danzo and a squad of ROOT Shinobi."

The Hokage looked shocked. His normally bronzed skin turned pale at Kakashi's words.

"Elder Danzo then began to attack Shisui and proceeded to steal his right eye. Shisui then body-flickered away but was confronted by the squad of ROOT shinobi. One of the Shinobi poisoned him with a cloud of gas before Itachi came to his rescue. Itachi swiftly dispatched the ROOT shinobi, before Shisui led him to the cliff above the Naka river."

"N-no, you can't mean..." Hiruzen said horrified.

"Yes, to keep Danzo from getting his other eye, Shisui entrusted it to Itachi, before jumping off the cliff. He did this to awaken Itachi's Mangekyou Sharingan, and also keep his body from being misused by Konoha's enemies. Itachi, not wanting to complicate the matter further, hid this from you."

Hiruzen looked down, his Hokage headpiece covering his face. He gripped his hands so tight, that they began to draw blood. A light red aura of Chakra bubbled around his frame as he suddenly shot up.

He lifted his head, and Kakashi felt a pang of fear. He resisted the urge to bow as he remembered why the other nations called Hiruzen Sarutobi the God of Shinobi.

Inside Hiruzen's mind, he was in a rage at the injustice that had fallen under his nose.

'Danzo, that slime! How dare he! Shisui-kun will be avenged, I swear it! And Danzo will realize why messing with the Hokage is a bad notion!'

"Kakashi!" Sarutobi suddenly barked.

His grandpa-like demeanor was gone. In front of Kakashi was the man they called the God of Shinobi.

"Tell me everything you know about Danzo! All of his abilities! Now!"

Kakashi's back straightened, before responding.

"Hai Hokage-sama! Elder Danzo was reported to have possession of Shisui Uchiha's Sharingan in his right eye. He had also had Orochimaru construct another right arm for him, that was fully made of Hashirama Senju's cells and had 10 different Sharingan implanted in his right arm. Since he had Hashirama's cells, he was able to use the fabled Wood element and the 10 Sharingan's were for the use of the Forbidden Sharingan Jutsu: Izanagi, which gave the user the ability to rewrite reality in exchange for the eye's blindness. In Danzo's battle with my student Sasuke, he repeatedly used Izanagi to avoid death."

Hiruzen grit his teeth.

'Danzo, how far you have fallen! It seems that I will have to end his life.'

Hiruzen suddenly looked up, his eyes sharper than any blade.

"Kakashi, after seeing everything you have shown me, I have decided that this village needs a change! The first thing I will ask of you Kakashi is to cut the tumor that is Danzo from this village. Kill him but incapacitate the other ROOT shinobi. I, myself will personally handle their therapy."

Kakashi looked a little unsure.

"Hokage-sama, wouldn't it be wise for me to train my abilities before confronting Elder Danzo?"

"Yes, this is why I am giving until the end of this month to prepare. On the 31st of March, I will ask you to kill Danzo!"

"Hai Hokage-sama!" Kakashi nodded.

"See to it that you prepare. Should I reserve a training ground?"

"Yes, Hokage-sama. That would be helpful." Kakashi nodded.

Hiruzen nodded and disabled the Silence Seal. Kakashi then quickly body-flickered away, leaving Hiruzen to contemplate over his thoughts.