Death's last words to him echoed in his mind; he decided not to make much of it. Harry found himself in a black void. Time seemed to be irrelevant here; it could be a millisecond, or it could be an eternity before he could see again. He found himself to be incorporeal, as a soul without a body, standing next to a four-poster bed.
He immediately recognized the room to be a Gryffindor's dormitory; judging by a book lying on the floor, Harry concluded it was the dormitory for second-year boys. And from Neville's and the traitor Weasley's snoring, Harry concluded it was well after curfew. Harry could tell his younger self-was in the bed right in front of him, behind the curtain. As he was incorporeal, he walked right past the curtain and saw his younger self. He looked so young and so fragile. He seemed to be troubled even when asleep, and it was time for him to put a stop to that.
The moment the incorporeal Harry Potter contacted his younger self, his older soul was sucked into the younger body.
Centuries of hunting dark wizards led Harry to become very cautious of his surroundings; the first thing he did after returning to his twelve-year-old body was familiarising himself with where he was and checking what was around him and if there were any threats. Harry kept his eyes closed and sent out a pulse of his magic. His magical pulse acted like a sonar and was reflected back to inform him of his surroundings. The sonar didn't work as well as it used to; despite retaining the vast amount of knowledge he gathered during his four centuries of past life, Harry seemed to need to train his younger body to relearn how to command magic like he used to. Nevertheless, he got enough information to confirm that he was lying in his bed in the Gryffindor's second-year boys' dormitory, and six magical people were sleeping in the room, including himself and the rat form of Peter Pettigrew.
Harry started to check himself over; his eyes remained closed. First, Harry checked his Occlumency; damn, alarms were going off all over the place. All that was left of his Mind World was the shell of his memory palace and a mostly destroyed control center. All his defenses and contingencies were gone; he would have to rebuild all that again.
Harry then found a series of complex charms used to stunt his mental capacity; normally, he would have to see a Healer about it, but with his advanced Mind Magic capabilities, even with a mostly destroyed Mind World, the blocks were already dissolving slowly. Harry decided to deal with the charms later if they were still not fully dissolved; first, he needed to check the rest of himself. For now, Harry disillusioned his memory palace, threw a massive invisibility cloak over his mind and added a beater bat for active defense.
Harry dived in further to find his magical core, or should he say cores. He found both his younger self's very powerful but bound core and his older, even more, powerful unbound core. Unlike in physics, where opposites attract, in magic, it was the other way round. Given the two cores were essentially the same core from different time periods, they were in the process of fusing as one. It really didn't make much difference to Harry's older more powerful core, for it was about a hundred times more powerful than his younger core without the bindings.
Once the two magical cores were fused together, Harry found the bindings that used to surround the younger core, now surrounded the much more powerful fused core. Of the thirteen layers of bindings Harry found around his core, only one was placed by his parents; the rest were all placed by the manipulative old bastard. Clearly, he needed to fix that. This time, he would choose carefully how to make use of all that magical backlash; Lady Hogwarts could definitely make good use of some.
Harry carried on checking his magical core; all the different colors represented the seven elements he now could manipulate. An area of grey patch represented his parselmagic, and the bright white remainder showed off his untainted core.
Harry then found the branches leading off from his magical core, draining power from it. With just over 0.012% of his magical core available, a third was draining to keep his parents and unborn sisters alive in stasis, a quarter was draining to power the wards in 4 Privet Drive, as well as all the monitoring charms on him, and a quarter was draining to sustain the Horcrux in his scar. This left him with only 0.002% of his magical core to use; even then he was still above the average British wizarding population without the boost from his older magical core. Harry was fully aware of how powerful he would become once he dissolved the bindings and shook off all these burdens. Hell, he lived with that much power for nearly four centuries. This was why he desperately needed to get his advanced Mind Magic capabilities back to what they used to be, so he could control his magic.
There were other branches indicating the oaths and contracts he was linked with, including those made by his godfather and godmother, but that was for another day.
However, Harry discovered something else literally made his blood boil. He found some branches indicating the use of blood magic. Upon further exploring, Harry found each of these branches was used to monitor a particular aspect of him: his location, his health, his magical core, his mental state and the Horcrux that was in his scar. It was then Harry made the connection to all the silver trinkets in Dumbledore's office; he would have to find a way to destroy these monitoring devices.
Harry then let himself become one with his magic and looked outwards to find his soul; he had learned how to do this during one of his travels in North America, where a Native American tribe leader taught him this to help him keep himself in check. As the saying went, 'Power corrupts, and absolute power corrupts absolutely.' Harry wanted to make sure he didn't become another Dumbledore. A bonus of this was, Harry could now find all of his animagus forms, as all their spirits lived in his soul, but that was a story for another day.
Harry first found his younger soul; he felt the characteristics of it: innocent, lonely, brave, pure and filled with hope. He then switched his attention to his older soul; again, he felt its loneliness, its bravery. But, its innocence was replaced by experience and cunning; its purity was largely retained, but tainted with a vengeful fire fuelled by his loss; and instead of being filled with hope, his older soul was immersed with loss and sorrow.
As the two souls merged to become a new soul, it recognized the second chance being given and took the best of both souls. Harry immersed himself in his new soul, its bravery, its cunning, its experience and its purity. The vengeful fire was replaced by a sense of righteous justice, the loneliness was replaced by the potential bonds of love, and lastly, there was the struggle between hope and sorrow; it seemed that his new hope needed some help to completely drive off the centuries of hurt and regret.
Like his magical core, Harry's soul also branched out. The souls of his parents and unborn siblings, frozen but peaceful, were connected to his soul by bonds of love. Harry knew it would be foolish to rush out to the family manor to revive his parents, and he was no longer a foolhardy Gryffindor. Harry wasn't sure when he would get the chance to revive his family, so he decided to ward his soul, especially the part anchoring his family to this plane of existence and set up an alert ward to warn him about anything that could threaten his family's survival. Harry then moved on to examine the rest of his soul.
To Harry's total surprise, there were seven shoots of new growth, all made out of love, each with its own uniqueness, waiting to be nurtured to become full bonds. This was something Harry was incapable of before his return; there was just too much hurt for his old soul to tether to anything new by love. Recognizing his second chance to live his life to the fullest, Harry made a decision then, to explore and nurture all these seven potential bonds. He already knew who each of these bonds would be connected to.
Harry then looked for the connection for the soul fragment of Tom Marvolo Riddle; he was worried about the possibility of corrupting and destroying the anchors keeping his family alive. Eventually, after thoroughly checking his soul, he concluded the fragment was not connected to his soul at all, at least for now.
Harry was delighted though, to find two new animal spirits, roaming around in his new soul. He would explore his new forms later; re-mastering his Royal Phoenix form was one of his first priorities.
Finally finished with his soul-searching, Harry decided to bite the bullet and discover how pathetic his physical body was. Harry mentally grimaced. Merlin, his twelve-year-old body was really a pitiful thing. There were improperly healed bones everywhere with barely any muscle attached to said bones, and scars all over his skin, especially on his back. Harry could tell that whatever was left available of his magical core was working overtime to keep him alive, and he was already starting feeling better with the boost to his magical core, but there was simply not enough nutrient at the moment to do any significant repairing. He would have to fix that before he completely dissolved the bindings on his magic; his weak body would disintegrate otherwise.
Harry then focused on the scar on his forehead and studied it carefully. It seemed that he had underestimated how literal it was when it was said that his scar was a Horcrux. The soul fragment was literally wedged between the scar and his skull; it had tried and was still trying to reach out to connect his soul, but there was a magical protective barrier keeping it from corrupting his soul.
The only reason Harry and Voldemort were able to look into each other mind was the proximity between the Horcrux and Harry's eyes and brain. A master Legilimens could read people's surface thoughts via passive Legilimency without eye contact, and Voldemort was a master Legilimens. But, neither the Horcrux nor Harry from the previous timeline was master Legilimens, the passage of information was solely achieved through the Horcrux and the top of Harry's eyes.
Harry smiled with pride at his mother's ingenuity. He had recognized the protective barrier from a sacrificial ritual in the Therion Family Grimoire; the same barrier protected him from the killing curse. Using the combination of these two ancient rituals, and some simple switching runes, his mother had ensured the survival of her family, if only the old goat had not meddled.
Harry had wondered why his family left the protection behind the powerful wards of one of his family manors in the first place; he suspected meddling on Dumbledore's part again. Oh, how he would draw out the destruction of Albus too-many-bloody-names Dumbledore, and enjoy every single moment of it.
Harry had wanted to exploit the soul fragment in his scar, gain all Voldemort's knowledge from before Tommy's body was destroyed by his mother, and maybe to use it to spy on the primary soul, of which there wasn't much left. It definitely wasn't much too far off to literally call Tommy boy a soulless bastard. However, Harry didn't want to risk corrupting his mother's ritual and losing the chance to revive his family, so he dived back into his magical core, found the branch draining to sustain the Horcrux, and cut off the supply.
Harry then redirected the cut branch and dragged it to connect it to the magical protective barrier, massively strengthening it. Harry went back to check on the Horcrux; it was already weakened and had given up reaching out to his soul. Harry doubted it would survive for long, but it might be able to from all the magic given off by him and the ambient magic in the Castle. In addition, the Horcrux might draw magic from other anchors to survive. As long as the fragment would not threaten the survival of his family, Harry would leave it be; he might get some use of it later after he revived his family.
Lastly, Harry checked the magical channels in his body. They didn't look good; in fact, they looked terrible. No wonder his magical sonar didn't work as it used to; the magical channels in his younger body were barely open. However, Harry was hopeful he would be able to dilate these channels to the maximum by the time he finished retraining his magic.
Harry opened his eyes after coming out of his meditation. It looked like he had quite a lot to do; this summer was definitely going to be busy. No longer the foolhardy Gryffindor, Harry needed a plan. First, Harry determined the exact date he came back to, as it would be a major factor in his planning. It was Monday, the 10th of May 1993, 0245. Harry searched back through his memories and remembered it was two days after his Hermione's petrification.
"Hermione," Harry whispered out her name.
Hermione, at her name, all other thoughts left Harry, except, Hermione's still alive, my Hermione's alive, petrified, but alive. After nearly four centuries since he last saw her, Harry immediately got out of bed and prepared to see his Hermione in the Hospital Wing; not even the manipulative old bastard was going to stop him. Besides, Harry just remembered Dumbledore's removal from Hogwarts. Good, Harry thought, he would be able to do everything without the manipulative old bastard monitoring his every move; and he had nineteen days to plan before Ginny was taken to the Chamber of Secrets.
Harry put on his Invisibility Cloak, and his glasses; he had nearly forgotten about that, something else to fix. Harry left for the Hospital Wing in a hurry. He didn't want to test whether he could use one of the magical teleportation methods he'd learned or developed yet with his younger body, so he put a silencing charm on his shoes, and raced towards the Hospital Wing.
He immediately found Hermione's bed after sneaking in and set up some simple privacy and silencing wards around her bed.
Slowly, Harry looked up to meet Hermione's petrified, but still open eyes. Try as he might, Harry couldn't stop the tears from filling his eyes. With his Occlumency shields down, once a single tear dropped out, the floodgate swung open. Harry dropped to his knees next to Hermione's bed, held her stone-like hand, and sobbed his heart out as he relived the day he learned of Hermione's death in the future, a future he would make sure to never come past again.
Flashback
It was ten days after his medical check-up upon joining the ranks of Unspeakables. How Harry managed to master Occlumency and Legilimency to control his immensely powerful magic in such a short time was a story for another time; let's just say, it involved a time compression chamber and lots of magical backlashes.
The newly dubbed Unspeakable, codenamed "Peril", came out of the time compression chamber and was ready to put this new dark lord wannabe down, but he needed to check on his best friend first. After the revelation about the youngest Weasleys and potions, he was worried about Hermione being Ronald's fiancée. He hoped against hope that Ronald genuinely loved Hermione, and hadn't hurt her, but with his mind thinking so much clearer, he couldn't help but draw the worst conclusion.
Harry Apparated straight out of the Department, to just outside the Burrow. He put on a fake smile and knocked on the door. As soon as Ronald Weasley had opened the door, Harry had sensed something was wrong. Weasley had become nervous the moment he saw Harry, a much taller, and much bulkier version of Harry, without his glasses, his emerald green eyes radiating power.
Ronald had nearly wet himself, trying and failing miserably to put on a fake smile, but to Harry Potter, Weasley was broadcasting his panicking thoughts; the moment Harry picked up the words, 'Hermione' and 'killed', Harry immediately reacted.
His wand was in his hand in a flash. Harry disarmed Weasley before the weasel even blinked; he then 'went muggle' on Weasley, using his newly acquired kickboxing skills to break all of Ronald's limbs. Weasley had just managed to let out a scream before Harry grabbed his neck and squeezed.
Harry wanted to learn everything, and he didn't want to be disturbed, so he let his magic do the work, and Popped. Out of all places, Harry along with the broken Weasley appeared on an island in the middle of a lake, a lake infested with Inferi. Harry still vividly remembered when he came here years before with Dumbledore, retrieving what they assumed to be one of Voldemort's Horcruxes.
Harry wasted no time; he immediately pinned the weasel down on the ground and dived into his mind. The more he learned, the angrier he got.
From Ronald's mind, Harry learned Ronald was never his friend; their first meeting was a set-up. Ronald was paid with his money to spy on him, keeping him from learning his heritage, keeping him isolated from the rest of the student population, as well as using his best friend's status to get away with whatever he wanted.
Ronald had knowingly fed him loyalty potion, mostly brewed by Molly, although some were given by Dumbledore. Ronald had tried desperately and failed to keep Hermione away from him, eventually resolving to feeding her love potions, jealousy potions as well as loyalty potions, and even then, Hermione seemed to be able to fight off most of the effects and remained loyal to Harry.
After Voldemort's demise, Ronald was pissed that Harry had survived. With Dumbledore gone, he was no longer getting paid, and he wouldn't dare go to Gringotts due to his involvement in the break-in. So he decided again to use his best friend's status and ride along using Harry's fame to get what he wanted. In his resentment of Harry's survival, Ronald kept feeding Hermione love potion with Molly's help.
Then there was Hermione's death. Their relationship had never been stable since the Second Wizarding War ended. Hermione caught him cheating multiple times, but kept coming back after breaking up due to effects of love potions; however, despite the love potions, Hermione never did let their relationship go beyond snogging, even after accepting his half-hearted proposal, which was one of the reasons why Ronald had kept cheating on her. Finally, thirteen days before, the weasel lost his patience, and tried to rape her; Hermione broke free from the potion's effects and fought back.
During the struggle, Hermione was thrown against a table and hit her head; she would have been healed if Weasley had immediately sent her directly to St Mungo's Hospital, but no, Ronald was busy gloating how he was finally going to have his way with her and to take away one thing Harry had wanted.
While Ronald was gloating, Hermione had slowly and discreetly got hold of her wand, and cast a castration hex on the weasel, before drawing her last breath, muttering, "I love you, Harry!"
Harry struggled to hold back his tears and kept on rummaging through Ronald's mind, to find out what happened to Hermione's body. He found the memory of Ronald, Ginevra, Percival, and Molly planning how to hide Hermione's body, and came up with the excuse of her disappearance due to the ongoing war. Halfway through their planning, Arthur walked in, and even he reluctantly agreed to not inform Harry of what really happened, not wanting to face his wrath.
When they decided what to do with Hermione's body, they started discussing how the plan of getting the Potter fortune needed to adapt to the situation. It was clear this was new to Arthur, but he couldn't back out now; Ginevra didn't care, as long as she would marry the Boy-Who-Lived/Man-Who-Won; however, Ronald, Percival, and Molly were in it from the beginning. Ronald and Percival only knew their parts in the plan from Dumbledore, whereas Molly knew the whole plan from Dumbledore, and had a few of her own. After they finished the new plan, Harry saw Ronald's memory of dumping Hermione's body in some river. Harry learned every detail around the river and came out of Weasley's mind.
To say Harry was furious was the understatement of the century. Weasley's eyes widened in fear as he now knew Harry had learned everything from his mind; he could literally see magic pouring out of his body, to the point it had become oppressive.
Harry no longer needed to hold back his tears, as there were none left; all that left was the fire of vengeance dancing behind two glowing emerald orbs.
Harry whispered in a voice so calm, it scared the weasel to soil himself. "You will suffer for all you did and more."
Harry then dived into the weasel's mind again, planted his memory of suffering under Voldemort's Cruciatus Curse, and trapped the weasel in that memory. Harry put in a safeguard to prevent the weasel from going insane before coming back out again.
Harry then conjured some metal chains with his wand to lock the weasel in place, so he could only reach the basin, but not the Inferi-infested lake. Without focusing on how, Harry waved his hand and parted the water in the lake, and lit all Inferi present on fire with the other hand, except for one. He then used his wand to put a timed activating charm on the single Inferius left, causing it to attack whatever was left on the island in a month's time. Only then did he allow the lake to refill, burying the single Inferius underneath the lake.
Harry turned to look at the screaming weasel and silenced him; he told the weasel in a chilling voice that would send shivers down Voldemort's spine, "Now you will know pain. You will scream until you are too thirsty to continue, then you will drink the potion in the basin brewed by Voldemort himself; it will force you to relive all your worst memories. You will do this for a month, and then the single Inferius I left under the lake will slowly and surely dismember you in the most painful way possible.
"See you in hell, weasel." With that, Harry disappeared.
Harry immediately Popped to the river in the weasel's memory. He put on a Bubble-Head Charm on himself and dived in. Harry swam for three miles downstream before finding Hermione's body; he then took her back to her parents. Together, they mourned for Hermione Jean Granger, Smartest Witch of her Age, beloved daughter, and faithful friend.
Kneeling in front of her headstone, Harry swore vengeance on all those who had wronged her and stole their chance of happiness. Before he stood up, Harry muttered, "I love you too, Hermione. I will make you proud before we meet again."
Flashback Ends
It took an hour for Harry to get his sobbing under control, knowing she could hear him from his future knowledge, he whispered to her.
"Hermione, I know you can hear me. Know that I will always love you, you don't have to hide behind books and authorities anymore, because you are mine to protect, forever. Also, thank you for figuring out about the basilisk; don't worry about me, I will not rush in without a plan. Trust me on this, love.
"Listen, something isn't right about Ronald, I want you to learn potion detection charms over the summer, and start to check all of your food and drinks in the coming year, especially those touched by any of the Weasleys.
"In the meantime, being aware but not able to do anything must be driving you crazy, so I want you to start learning Occlumency. I will start teaching you now. Occlumency is a branch of magic called Mind Arts, the opposite is called Legilimency. Occlumency protects your mind from being read by Legilimens, which is a person capable of performing Legilimency. Master Legilimens could read your mind without using a wand, and yes there are two professors I will not name for now that are master Legilimens, and I will now teach you how to protect yourself from them.
"There are many levels of Occlumency. The basic level will only alert you from being read by inexperienced Legilimens, but a master will still be able to read your mind without detection. At the next level, you will have a much stronger and thorough shield, and it would be much harder for anyone to read your mind without being detected, but a Legilimens could still brute-force through and pull out your memories. At an advanced level, you will be able to suppress your memories, emotions, thoughts on top of your shields, so that even if a Legilimens broke through your shield, they would still have trouble pulling out your memories. In addition, you will have more resistance to mind-altering curses, potions and charms, such as the Imperius Curse, love potions, and compulsion charms.
"And at Master's level, you will love this, Hermione. A Master Occlumens has a fully formed mindscape; the mindscape serves to organize your memories and thoughts, and you can then add shields, tripwires, traps and anything else you could think of to protect your memories. With a fully-formed mindscape, you will find yourself better at remembering details, to the point of having perfect recall. Imagine how many more books you will be able to read, Hermione. I know I said you don't have to hide behind your books, but I also know how much you value knowledge, and I would never want you to change a part of yourself. But please remember, not everything written in books is true.
"Now that the introduction is over, do you want to learn this? I don't need you to answer to know that you do. Knowing how your beautiful mind works, I'll bet it's already very much organized, most likely to a library-like mindscape. But regardless I will start at the beginning…"
Harry then spent 2 hours teaching Hermione how to meditate, even without breathing exercises, given her petrified state. He taught her how to find her mind, how to start building her mindscape and gave her examples of different people's mindscapes. He then let her know the benefits of having a memory palace built within her mindscape. Lastly, he taught her about the different kinds of defenses she could put in her mindscape, and how it's better to build her walls brick by brick instead just setting a huge slab of stone.
"Now I am sure that was quite a lot of information to process, and you have got a lot of work to do to build your mindscape, so I will leave you to it. Remember, it's worse to have an organized mind without adequate defenses, as it would be even easier for the Legilimens to pull the correct memory out. So I am going to set you your homework, I know how much you love doing homework, hehe. You should wake up in about twenty days; in these twenty days, I want you to organize your memories, thoughts, and emotions into your memory palace, and next, I want you to build a mindscape around your memory palace. I want you to build an impenetrable defense with passive shields, as well as active defense systems with dragons, cannons, et cetera. When you wake up, I will test you, Ok?
"If you have any naughty memories you want to protect, make sure your defense is impenetrable. Remember, it's your mindscape, therefore everything in it should and will follow your laws; you need to know every inch of your mindscape, only then you will be able to will everything to follow your laws. So be patient, and build your mindscape one bit at a time.
"Goodbye, for now, I will come back to talk to you later; remember, I will always need you and I will always be there for you. You are my best friend, and hopefully one day, something more."
After visiting Hermione, Harry felt much lighter; he had held that in for nearly four centuries. Despite how much his later lovers had tried, Harry could never talk about her, until today. He could feel hope in his soul again.
Taking down the wards, Harry snuck out of the Hospital Wing, and pondered his next step. Repairing his own Occlumency was definitely the top priority, especially since with Dumbledore's charm in place stunting his mind, he couldn't think properly. It was seven o'clock already, so the once-again-growing boy decided to take a trip to the kitchen to get some food, and find a secluded place outside the Castle to work on his Mind Magic for a couple of hours, before heading to potions. He was too paranoid right then to go to the Room of Requirement; it was one room he didn't want the manipulative old bastard know about.
Twenty minutes later, he was alone facing the lake, a tree blocking him from prying eyes from the Castle. To say Harry Potter was a master at Mind Arts was like saying Dumbledore knew magic; true, but grossly understating.
Flashback
Upon receiving the results of his medical check-up, Croaker immediately ordered the Healers to remove his mind blocks and administer the strongest flushing potion to remove any residual potions. Croaker then told him that he couldn't risk removing the bindings on his magical core, without having him master Occlumency first. With the ongoing war, there wasn't much time to teach him, and the time compression chamber in the department was still recharging.
Harry nodded, glad someone was upfront to him, and then an idea came to him. He asked Croaker if they could remove the bindings a layer at a time, and use the magical backlash to charge the time compression chamber.
Croaker was very agreeable, and told him they even had crystals that acted like magical batteries; they were usually placed close to the ley lines to collect magic for emergency use, but they had used up all of them. So Croaker took him to a sealed ritual room with twenty crystals in it; each could power the time compression chamber for a day.
After dissolving three layers of bindings, all twenty of the crystals were fully charged. They decided to go into the chamber for ten days; each real day outside was a year inside.
Given the state of war, Croaker brought five other new recruits of the Battle Unit to train and a Healer for Harry and the team in the time compression chamber. During those ten years, the Healer worked extensively on Harry, and at the same time, Harry and the team trained under a foreign Battle Mage who had been retired for decades before being called in as a trainer for the newly formed Unit. During his spare time, the Head of the Department of Mysteries taught Harry one-on-one on mastering Mind Arts.
Flashback Ends
Croaker had taught him all he knew about Mind Arts, which was as good as, if not better than Dumbledore's capability in Mind Magic, but that was only the start of Harry's journey of learning Mind Arts.
Over his decades to centuries of travelling, other than a small number of very well hidden magical communities, Harry had visited almost all other magical communities in every corner of the Earth. He had studied with all magical beings: humans from all culture backgrounds, Veelas, Goblins, House-Elves, Centaurs, Vampires, Merpeople, he even found the rumoured-to-be-extinct High-Elves, and that was not to mention the Great Dragons.
Harry didn't consider Werewolves as a separate group, as he thought of them as magical humans with a disease, a disease with a cure Harry had a major role in developing.
The studious wizard had learned all types of magic from each of these groups, but he had always focused more on Mind Magic and Battle Magic. Magic is magic; however, each species or culture had a different way of using magic, including their use of Mind Arts.
For instance, Goblins would always protect their client's privacy as well as protecting their ward schemes; thus they all had almost impenetrable defences, whereas House-Elves were more adapted at reading minds to anticipate their master's wishes. Veelas on the other hand, were much better at misdirection; you would never know if what you glimpsed from their minds was real or not.
For Harry, he had took the best from everything he had learned, mixed with what muggles had understood about the brain and computers, which by 2098, were quite advanced, and he built his Mind World from all these together.
As he dived into his Mind World, dropping into his control room, the time-traveller found himself to be in his older form again. He first checked on his Memory Palace, which took the shape of Ravenclaw's Castle. No living beings other than him had seen it in more than eight centuries.
Harry then Shifted to the location where he stored a backup of his Mind World, and unlocked the security vault using a Parseltongue password. Once inside he had to find the correct locker, unlocking it using a conjured key; he then took out a copy of the disk, locked up everything again, and Shifted back to the control room.
The disk contained the schematics of the latest version of his Mind World before he returned to the past. Using a biometric palm scanner to activate the master control, he loaded the disk, and using a 256-bit encryption key he had memorised, Harry started the decryption process. As there were three layers of encryption, it took two hours in his mind to finish the decryption process; however, due to his magical power, and years of practicing Mind Arts, in reality, only ten minutes had passed. It would only get faster when his magical core was unbound.
He then tasked the master control to rebuild his Mind World using the schematics on the disk, and to run diagnostics to find out what destroyed his Mind World during his rebirth. Lastly, Harry activated the heads-up display (HUD), so he would be able to watch the rebuilding process as well as access his Mind World when he came out of his meditation.
The rest of the processes were all automatic, but Harry knew time barely passed on the outside, as the newly rebuilt world clock displays just came online in his control room. Harry had the expression of a kid at Christmas, as his control room looked more and more like a control centre, and one by one, his Artificial Intelligence (AIs) came back online. Finally, the Control Centre had finished rebuilding, and all his AIs went through diagnostics and started working furiously to rebuild the rest of his Mind World.
Immediately, one of the AIs detected the stunt placed by the MOB, a term Harry started to refer the manipulative old bastard Dumbledore as; the stunt was disintegrated very quickly, and due to this, everything else happened even faster than before.
Starting from the entrance of his Mind World, the master Occlumens had a replica of Hogwarts Castle as well as its surrounding grounds, including the Forbidden Forest and Hogsmeade. This castle was designed to lure and trap enemies; it looked just like the welcoming Hogwarts School of Witchcraft and Wizardry to put intruders into a false sense of security, as well as letting the intruder assume the Castle was protecting his memories. Where in fact, all memories contained in Hogwarts Castle were either fake or very painful.
The intruder would always arrive at the Hogsmeade station; as soon as the intruder walked past an invisible ward line, all previously inactive and disillusioned defences would become visible and start attacking the intruder. The defences included many dangerous species of magical beasts, including basilisks. From above, there were also Apache attack helicopters. The intruder would be forced into the castle, if he managed to stay alive that long, and locked in. Harry would then be able to control the castle to direct wherever he wanted the intruder to go, experience whichever memory he wished the enemy to experience, and only Harry could personally escort the intruder out. Of course, Harry would be able to memory-charm the intruder before he left, or he could lock the intruder's memory so as to not be able to tell anyone else of the incident.
Harry would often exploit the intruder's state of panic, and sneak a Trojan horse into their minds, which would slowly compile information in the intruder's mind in small data packs, without being noticed. The data pack would then be placed on the surface thoughts of the intruder's mind as random numbers, allowing Harry to download information slowly even after the intruder was escorted out of his Mind World, just by scanning their surface thoughts. Once all information was downloaded, the Trojan horse would constantly build update packs for any new information.
Perhaps, what was even more ingenious or sinister, depending on how you looked at it, was the Trojan horse within the Trojan horse; the second Trojan horse serving to corrode one's mind, but dormant unless an activation phrase was whispered by Harry, and heard by the intruder. Of course, this Trojan horse would more likely be discovered by skilled Occlumens and thus destroyed, but the damage would have already been done. Harry was going to make one each specifically for Dumbledore and Snape, making sure they suffered as much as possible.
His false memories also served another purpose; with a full set of fake memories in Hogwarts Castle, Harry could overcome the most potent truth potion, by simply temporarily setting his mind to recognize the memories in Hogwarts Castle as real memories. The AIs would also be able to create detailed memories to put in Hogwarts on-the-go as he was being questioned.
His real memories, though, were all placed in the replica of Ravenclaw Castle; it also contained all the valuable knowledge he'd gathered during his four centuries of life in the other timeline. Ravenclaw Castle also served as his central command, and was placed on the far side of the moon, where no one would ever look. The castle itself was disillusioned, with an invisibility cloak covering it; it had many active defences: machine guns, grenade launchers, land mines, and twelve Hungarian Horntails patrolling around the structure. The moon itself had multiple disillusioned drones circling it, ready to attack anything getting close.
Although Harry himself could drop straight into the central command, for everyone else there was only one viable safe entrance, through a paired, upgraded version of the Vanishing Cabinets, redesigned by himself during the 2060s for the Department of Mysteries, commercially called Potter's Portals. The pair in his Mind World had top-of-the-line biometric security measures, top-of-the-line for 2098: voice recognition, again, a Parseltongue password; biometric palm scanner, keyed to his left hand; and retinal scanner, keyed to both of his eyes, with a blinking pattern in Morse code as the last security measure.
One portal was placed just outside the entrance hallway of the Ravenclaw Castle, with a team of eight AIs armed with assault rifles guarding it; its sister portal was placed in the deepest part of Hogwarts Castle, in Salazar Slytherin's library located in the Chamber of Secrets. Tommy-boy had never found the library, as he had been deemed unworthy of the knowledge in it. The Chamber had a King and a Queen Basilisk; both would only answer to Harry's command, instead of any Parseltongue.
Lastly, a copy of all the information stored in Ravenclaw Castle was placed in a replica of Potter Manor in Wales, which was placed in one of the thousands of stars in the sky. Only Harry knew which star it was on; however, he designed it so even he couldn't access that star. Once built, everything in Potter Manor would run remotely by a pair of AIs; one AI was to collect every piece of new data in Ravenclaw Castle, authenticate the data and copy it in its encrypted state to be placed behind layers of security in Potter Manor, while the other AI was designated with a single job to look for discrepancies in Ravenclaw Castle, by checking the data in it against those stored in Potter Manor; this would counter any form of memory charms. The defence system around Potter Manor was similar to that around Ravenclaw Castle, except the use of battle spaceships instead of drones.
A lot of Mind Arts is about will, and one's will could be strengthened by practicing Mind Magic; of course Harry Potter had one of the strongest wills naturally, being able to fight off an Imperius Curse on his first try when he was 14 showed that. However he had kept on strengthening it; he had security measures that would immediately alert him if someone was to try to control him in any way, Imperius Curse, Compulsion Charms, mind altering potions and repelling wards or notice-me-not Charms.
Harry now had the strength to fight all these off the moment he was made aware of any attempt, and he could decide the manner in which he fought off the attempts. It didn't really matter most of the times, but if someone was casting Compulsion Charms or Imperius Curses on him, they would be in a world of pain. If the master Occlumens chose to, the offender's will would be directed to a long, thin room. The room used an upgraded version of the Electromagnetic Aircraft Launch System, but instead of aircraft, the system would launch a block of metal, weighing two tonnes, accelerated for two miles, straight at the offender's mind. Whoever tried it would most likely spend months in St. Mungo's with the Mind Healers.
Harry Potter knew he had the best defended mind in history, but he wasn't arrogant enough to assume no one else would ever delve into Mind Arts as much as he did, so he prepared contingencies for when the opponent had better strategies, trying to sneak into his Mind World. Everything in his Mind World was constantly scanned for malicious objects; if something was found and couldn't be dealt with, a master reset could be used to destroy and rebuild his Mind World with all his memories intact.
Of course, defending his mind was only one of the many functions of his Mind World; he had built an ecosystem to allow all his animagus spirits to live in freedom. The multi-animagus also benefited from their roaming freely in their natural habitat, as he could learn how they moved; granted, Harry still needed to train in those forms in the physical world, but it was better than nothing.
The library in Ravenclaw Castle, as well as Potter Manor contained thousands of tomes. The well-travelled mage had used his perfect recall developed from his Mind Magic and read every single book he could get his hands on; he reasoned that he felt closer to Hermione that way. But he had not processed everything he read; there were many books Harry had simply copied to his mind by speed-reading through them. Therefore, he or his AIs could use the study room attached to the library to do research.
However, despite how much greater control Mind Arts had helped with his magic, as a security measure, Harry could not practice magic unknown in his Mind World, so he had to practice new spells and playing around with runes in the real world. However, the duelling room in his Mind World was a great place to develop spell chains, and duelling strategies nonetheless.
Harry watched as the last piece of his Mind World finally fell into place, and discovered he had twenty minutes to get to Potions. So, he came out of his meditation, and smiled as he saw his HUD up and running, reporting the diagnostic scans and displaying any information he had on everything he set his eyes on.