Harry followed the Light arrow out of the Ravenclaw dorm and up the stairs. Harry continued following it, memorising the path he was taking towards where ever he was being taken.
Soon enough he found himself facing a large door that formed itself out of the wall. Harry knew the location from the books. It was the room of requirements.
Harry entered the room and found a large cubical stone being bound by what appears to be chains of red liquid that Harry assumed to be blood. The light arrow reformed itself into a sword and swung down on one of the chains.
Harry being Harry decided to study the chains first, in case he needs to reseal whatever it was he was releasing. After a minute of scanning Harry confirmed two things. One, the chains are made of blood and souls. Two, even though there isn't such a thing as evil, magic but evil magicians, Harry really hated these chains.
The chains need the sacrifice of children souls and blood to form dark enough energy to hold whatever is being bound. The good thing is that the souls have already crossed, so there is that silver lining right?
Harry didn't hesitate anymore and materialised his blade. He coated it with pure magical force and struck. One by one thirteen chains fell and dissipated. With each chain the stone would hum in joy.
When the last chain fell light began emitting from the stone. The castle shone in light itself. Old scars on the castle walls started healing. Castle stones cleaned themselves and made it so they are flat in the wall. Dark corridors had proper lighting and the castle armour suits rearranged themselves to cover all areas of the castle. There were no blind-spots allowed.
"God it feels good to be free again" a voice called from the stone as light began to converge and form a sort of cocoon "return to your room young champion, all will be explained tomorrow
Harry knew who it was, and he was not about to get himself in trouble with a sentient castle" he was spending the next seven years in "as you wish lady Hogwarts" Harry bowed and left, not caring anymore as it was, as they say, not his problem
On his way back he stopped by the kitchen and dropped off a few cooking books for the elves with a note. It read:
"To be better cooks, learn from the books. If you need help, ask the Potter elves" the note was not signed and would vanish by noon the next day
---
The next morning was uneventful… for Harry. The rest of the castle was not as fortunate however as they woke up to the sight of Hogwarts looking immaculate, like it was built yesterday.
Confused students and teachers were trickling into the great hall. Nothing was changed, other than the newer looking… everything; it was the same, almost. Dumbledore's throne like chair is just a normal professor chair now.
Once the all the professors, but Quirrle-mort were present and seated a young woman appeared with a flash. She was relatively tall, had beautiful long golden hair and same coloured eyes. She wore purple coloured robes that showed little to no skin but fit her snugly, emphasising her curves.
She stood at the entrance of the great hall as if waiting for something.
McGonagall was immediately on guard and asked "who are you and how did you bypass the wards?"
The woman smiled and as if on cue Fawkes showed up carrying the Hat. The hat dropped on a stone column that rose from the floor while Fawkes perched himself on her shoulder.
"Greetings, lady Hogwarts. You certainly took your time to wake up" the Hat spoke surprising everyone
"it was that damn Alecto" her face contorted in disgust "she detected my waking up and didn't want her power to shift, so she sealed me and erased all evidence of where my core exists" she explained
"May I ask what is going on Hat?" Dumbledore came to the two
"Hat?" the woman, Lady Hogwarts asked
"They don't know who I truly am, my lady" the Hat explained then turned to Dumbledore "she is the embodiment of Hogwarts, and is as such the castle's Lady. She was supposed to awaken a couple hundred years after the castle was built. It seems, however, that the previous headmistress Alecto Murices sensed lady Hogwarts awakening, and decided to seal her instead of allowing her to take her freedom from her"
"And we are supposed to just accept this?" Snape put in his two scents
"I can't hire or fire, nor can I do anything to harm the residents of the castle" Lady Hogwarts explained "my job however is to protect the students and to record and monitor all the castle's matters"
If Dumbledore was bothered by anything, then he didn't show it "Lady Hogwarts, the wards control is supposed to be with the headmaster of the school, it had been this way since the times of old" he explained with his usual grandfatherly demeanour
"And it had been wrong since then" she replied "the wards are part of me, no one will bind me again" she spoke with authority, as the weight of the wards fell on the teachers, she then rounded on Snape "I'm not allowed to harm the residents of the castle, unless necessary… try me" she was staring Snape down, while her eyes shined with a golden light and her hair floated behind her
The pressure was suddenly released and she turned to McGonagall "you can't be both deputy headmistress and head of house. Choose one as in the rules a student can request both to be present in a meeting with the headmaster. Also, how do you find time for your students doing both jobs?" she then turned to Dumbledore "Binns was removed from his position as the history teacher"
As she turned to leave Dumbles spoke up "I thought you couldn't fire people?"
She stopped and turned to face him "I didn't fire him, I exorcized a harmful ghost" she explained with a smile before vanishing, leaving the great hall in a frenzy