The Battle of Hogwarts would be remembered as the shortest and bloodiest battle in wizarding history for many centuries to come.
When the wards fell, it took only seconds for the first lifeless bodies to hit the ground. In the 17 minutes it took for the war crime Aurors and a small army from the ICW to arrive at Hogwarts, the grounds were already littered with dead, injured, and mutilated wizards and witches from both sides.
In the 60 seconds, it took for the newest arrivals to come to grips with what they were seeing and ready themselves to attack, a shift in energy on the school grounds turned battlefield drew everyone's attention to Severus Snape: Spy, Professor, and Unofficial Adopted Father of one Harry Potter, dueling the Dark Lord by himself. They had been dueling since the wards had broken but the cause for all the surrounding combatants to become distracted with their duel was seeing Severus Snape being hit in the chest by an Avada Kedavra he could not dodge.
For a moment, it was as if the world and everyone with it suddenly held their breath. Before that breath could be released, before Voldemort could grin at killing the traitor, before anyone had the ability to turn back to their own bloody battles, a shockwave exploded across the grounds.
Harry Potter: Spirit Guide, Poltergeist, Forever Age 7, Ex-Boy-Who-Lived, and adopted child of Severus Snape, exploded with energy and anger seeing Severus, HIS Severus, being killed by Voldemort. The resulting shockwave knocked everyone within a kilometer of the school on their ass, the weaker ones being knocked unconscious, even the great Dark Lord Himself stumbled and nearly fell over before focusing his attention on the crackling ball of angry energy and magic that Harry had become.
There were no grand speeches, no gloating, no snide comments, no time to say anything before that energy slammed itself completely into the Dark Lord's chest. For a moment there was only a slight widening of Voldemort's eyes to indicate anything had even happened, before Voldemort was on the ground screaming, writhing, fingers digging at pale skin, begging for the pain to stop. The proud Dark Lord falling apart in front of everyone was a scene that would haunt nightmares and stain history books.
Just as quickly as Voldemort's screams had started, they went silent before his body burned with a blinding white light. When the light faded and everyone was able to blink past being so suddenly sun blinded, they saw Voldemort burned to a crisp. His body looked more like a piece of charcoal than the powerful wizard that had stood there only minutes before.
Death Eaters and their allies surrendered with little fuss, the dead and injured were gathered and seen to, and among the loud celebrations, only Filius seemed to take notice that Harry did not reappear after the death of Voldemort.
He wondered if killing the Dark Lord just burned up all the energy that allowed Harry to exist. But then again, Harry just lost Severus, and he knew the child knew that he couldn't cross over to the other side, meaning he just lost another parent, his only loving family that he could remember. Filius quietly mourned for both Severus and Harry, lives cut too short and destroyed in a war that could have been prevented. It was that moment that Filius Flitwick promised to himself and to Hogwarts that no matter was reporters wrote, what the Ministry said, or what would be published in history books to come, he would tell the true stories of Severus Snape and Harry Potter to the students of Hogwarts every year.
Hogwarts would memorialize who they truly were. Hogwarts would remember them even when the rest of the world would forget. They owed that much to them.
—-
Friday, May 1st, 1994.
11 Days after the Bloody Battle of Hogwarts.
The Memorial to those who had died during the reign of Voldemort was erected on Hogwart's grounds where Severus had died and Harry defeated the Dark Lord for good this time.
Over two thousand names covered stark white marble pillars. Wizards, witches, house-elves, giants, goblins, centaurs, and one ghost. Anyone from either side that died was upon those pillars.
After the memorial service had been held, what remained of the staff had gathered in a mostly intact staff room to mourn, drink, and make plans for repairing and restarting Hogwarts. It was during a lull in their conversation they heard a commotion out in the corridors. Most refugees had left Hogwarts already, but many had nothing to return to so they still stayed inside the school's walls and reconstructed wards.
"A teacher's duty is never done." Filius sighed, before standing to go see what trouble was being made in the halls on a day that should have been respected and reserved for mourning and reflection.
Pomona and Poppy followed more out of curiosity than any need to back Filius up. Especially when once out in the hall Filius seemed to have frozen in place staring down the hall. Poppy was immediately concerned someone had hexed Filius and was whipping her wand out to check him when Pomona gasped from behind her. She looked up and realized what had happened.
Down the hall, in the middle of the corridor, were two figures. The larger one was scolding the smaller one in achingly familiar dulcet tones. Both figures were see-through and hovering a few centimeters above the floor.
"What were you thinking?! You know the danger of completely burning out what magic you have, you could have ceased to exist on any plane!" Ghostly Severus Snape lectured a guilty-looking 7-year-old Harry Potter. Assuming Harry used his superpower of puppy dog eyes on Severus because he quickly crumbled and pulled Harry in for a firm hug filled with worry and love.
Filius regained his composure and cleared his throat drawing the attention of Severus and Harry. "It is so wonderful to see you both," Filius said quietly if still a bit sadly. Unexpectedly Severus smiled in a way that Filius couldn't remember him ever doing, even when he had been a young boy. It was a smile free of burden and duty, it was open and unreserved.
"Do not mourn me, my friends. I am where I am meant to be. Taking care of this trouble maker." Severus grinned and ruffled Harry's hair, making the little boy beam up happily at Severus.
"I expect that this is the way it was meant to be," Pomona said sagely.
"Kids need their parents." Poppy said happily, "Even ghost kids I suspect."
"You do not want to know what Lily threatened to do to me if I had not returned as if I was going to do anything else." Severus rolled his eyes, making the professors chuckle.
"Welcome Home Severus, Harry." Filius nodded to both of them, making both of them smile. They were home and they had each other.
—-
It took another year before Hogwarts was back in order to open as a school again. When they welcomed students back in September of 1995, a lot of students had missed almost 3 years of schooling, so they were welcomed with an opening feast and sorting was held off until everyone could be tested and placed in their appropriate school year. With so many new students and new staff, it was a chaotic start to the year. But among the students starting their 3rd year of Hogwarts was one, Harry Potter, beaming and talking with friends as if the war never happened. At the staff table sat one ghostly Severus Snape, having refused to add to the professors that are ghosts, he did agree to remain the Head of Slytherin House, mostly because he didn't trust anyone else with his snakes.
It was chaos. It was wonderful. Severus had never been happier, and neither had Harry.
Harry and Severus would remain at Hogwarts even when the oldest of the ghosts had been convinced to pass on. Just as Filius had promised, their story was told to all of the students on the memorial of the Battle of Hogwarts every year. Not that Harry or Severus noticed much. Harry got to keep an eternal Dad that loved and cared and taught him as he performed his duty and helped other ghosts pass on to the next life in peace.
Death and Fate weren't completely cruel.
Most of the time anyway.
The End