Doom Days (Harry Potter/MCU Crossover)

Pre-Chapter A/N: Happy Holidays Everyone. Here's this week's chapter right on time for your enjoyment. The next two chapters are up on patreon (www.patreon.com/Oghenevwogaga) as always. There's a handy little December discount on both monthly and annual plans. If you just want to read complete chapters and not my work in real-time then feel free to purchase this story as a collection on my pa-treon page- nice way to support this story, and me while you're at it. Enjoy! 

When I asked Flitwick for lessons, this is not what I'd expected at all. "You use your body to avoid attacks so that means you need to ensure your boy is capable of moving quickly enough and for long enough periods. You can not rely on your magic as a sole crutch in these matters. If you want to win the U17s this year, you will be going against wizards just shy of their magical maturity. You might be more powerful than anyone your age, but against those outliers, you won't have a drop of magic to waste" The Half Goblin said from his position on my back. I had not expected the Charms Master to be such a trainer but the man had given me his word to train me and it seemed that meant something to him. He was nothing like the species he inherited his height from, it seemed. 

"Faster, Potter. The sun is about to rise" He said and I sighed before picking up the pace of my run along the Great Lake. Physical training was grueling enough, but his requirement that all training take place and conclude itself before sunrise to prevent us from being observed was proving to be quite problematic. Sure, he was allowed to train me as long as he was not training me for any specific tournament events, of which we had yet to be briefed, but the fact that he was training me at all was information that was valuable to the both of us for different reasons. 

He didn't want to be inundated with endless requests for training, or worse be considered partial by his own students for choosing to train me but not them. For my end, if people didn't know I was training with Flitwick then they wouldn't expect me to use the duelling style for which he had become famous. 

"Yes, Professor. And about my request?" I asked, raising the matter we'd discussed after the previous day's session. 

"While I still find myself unsure of where you have found a pensieve of all things, I do agree with you that it will be one way to accelerate your training. I will give you memories. But to make sure you use them wisely, I will only give you one memory at a time. You will watch the duels and during our morning runs, you will discuss the duels and the takeaways you have gotten from them" He said, and I smiled and acquiesced. His demands were reasonable, and the important bit was that he'd said yes to giving me access to his memories. Flitwick had competed on the international stage, so that meant that he had gotten to watch some of the most dangerous and skilled wizards and witches in the world ply their craft. I finished my last lap around the lake, and wasted no time in taking us back to the castle. The walk up to the Sixth floor had killed my legs for the first few days, and right now I was not in the mood for that. 

"We have passed the stairs, Mr. Potter" The half-goblin said but didn't seem to mind. 

"Just taking a shortcut, Professor" I said before we appeared at a painting of a woman with long gown. Kathryn the Modest, the painting's inscription marked her as. I made a motion like I was attempting to look under her skirt and the woman with the long face harrumphed and turned around to leave the painting with a huff. As she did so, the painting swung open to show a secret passage. This was one Riddle had never found, but the Marauders had. I wondered how they would have compared when it came to knowledge of the castle's secrets. 

"How fascinating" The Charms Master said, waving his wand around like he was trying to detect something. 

"After you then, Mr. Potter" He said. 

I nodded and stepped through the hole. He followed suit and the painting swung close behind us. Lighting up my wand, I led the way. This was an interesting secret passage because it seemed like all it did was warp space between two fixed points. Unlike most other passages that ran as part of a network with multiple entrances and exists, this one just had one entrance, and the sole exit was exactly ten steps away. If one went any further than ten steps, they just kept walking and walking for eternity. Things like this were what made me suspect that at least one of the Marauders had some seer in them. My money would be on Sirius Black in that case, I thought either a chuckle, and then I froze in my tracks. Fuck. Sirius! I'd forgotten him almost completely. 

Flitwick looked at me quizzically so I just brushed off the thought for later and reached out towards the wall and pressed on one particular lose stone to make the wall turn into a door that swung open. We walked through and Flitwick actually gasped. 

"How fascinating. Only fifteen steps and we're all the way on the seventh floor? I hadn't even felt myself be translocated. How fascinating. Surely you don't mind if I study this in my own time, Mr. Potter" 

"Go ahead, Professor" I said to him. 

He seemed like he wanted to cancel the rest of our scheduled morning training to study the passageway, but thought better of it and followed me as I made my way to the stairs to go down to his classroom. I pretended not to notice the time he spent staring at the Portrait of the woman with the long gown and imperius face before he gave up and waddled along to join me. 

"Was that- was that the same woman?" He asked. 

"Best I can tell, yes. The passage only works one-way, in the sense that I've used it to come up so now I must use it go down if not I will not be able to use it to come up at a late date. It's kind of like an elevator" 

"An ele-what?" He asked instantly. I remembered just where I was and who I was talking to with a shake of my head. 

"Nevermind, Professor" I said instead, and while he still seemed curious, he did not ask any other questions. In fact, he was stuck in his thoughts until we arrived at his classroom. My legs thanked me as I fell upon a seat and I wondered how bad they would have been if I'd gone up six flights instead of down one as I just did. 

"Today, Mr. Potter. We will be working on shield charms" he said and I nodded. 

"So how many do you know?" He asked. 

"Just the general protego. Most books suggest that is more than enough and covers most situations" I said. 

"Yes, that is correct. For an auror or a hit wizard, maybe. But you are to be a duelist. No duelist worth his salt can get by with just a single shield charm." He said instead. 

I nodded, silently signaling him to continue with his lesson. 

"Different shields are useful for different purposes. For example, the protege shield is the most efficient way to block most spells and with enough power, one could use it to fly far above its broom class. The only issue there is that it becomes much less efficient when you do that. Also add the fact that it is useless at blocking physical objects or extremely dark spells like the unforgivables." 

"No shields can block the unforgivables" I instantly cut in, saying it almost by reflex. The words were almost burned into my mind. Both Tom Riddle and Harry Potter had researched that fact extensively. Tom as a way to counteract the spells that he was beginning to find so useful in his teens, and Harry Potter as a curious eleven-year-old trying to understand the source of his fame. 

"No magical shield. A conjured shield could block a killing curse just as well as any other physical object. Of course, the magic inherent in conjurations mean they tend to fall apart after facing only a single unforgivable but those rarely tend too get sent en masse" He said with a wry smile that I returned with an awkward one of my own. It was in conversations like this one that I learned just the kind of trauma that the world had been exposed to in the first war. I had no idea the kind of role Flitwick had played during the war, but I did know that it had marked him just as surely as it had scarred Mad Eye Moody. 

"But beyond that, shields like the aegis shield have their own uses. The golden barrier tends to be more magically intensive, but it can be maintained wandlessly and reshaped at will" he started the lecture. I nodded to show that I was paying attention as the Charms master dove into a subject that turned out to be a minor passion of his: shield charms. 

XXXXX- THE HALF-GOBLIN 

"And that is the last shield charm of the twelve" he said to his seemingly entranced student. If anyone had told him just six months ago that Lily's boy would be seating through an hour's lecture on specialized shield charms of all things with full attention, he would have laughed in their face. If they'd told him that he would be training Lily's boy on duelling, he would have actually had them sent to Saint Mungos for a check up. Yet, somehow both of those things had turned out to be true. 

"What about the protege diabolica?" His new protege asked, hands steepled in front of him and eyes glinting with undisguised interest. He felt his heart quiver at those emerald orbs and that look in them. He wouldn't lie. In the boy's earlier years, he'd paid special attention to him hoping to see this very look in them. He'd spent many a nightcap mourning the absence and the fact that that part of Lily had not lived on in her son. It just turned out that he'd been looking too early and the boy only needed time to come into his own. 

"First of all, you're highly unlikely to find much usage in the protego diabolica within a sanctioned duel. It is useful for screening between friend and foe, but none other than Gellert Grindelwald himself have ever managed to modify the spell to block offensive spells as well" he explained smoothly, enjoying the look that showed the boy was taking in the information given and assessing it before digestion. It was what he found lacking in so many from his own house: skepticism. Harry Potter was skeptical. That was the best way to put it. Just like Filius himself as a child, he did not find it easy to reconcile the words impossible and magic as working in the same sentence. 

Still that mindset would serve him well…for a time. Just like it had served Filius until it had become more of a hindrance than a help. Understanding one's limits would become more useful than self-belief as one went up the ladder, but that was not a question for the present. For the present? He had to get the boy in front of him ready for the U17 tournament in seven months. For good or for ill, after multiple sessions, he had begun to buy into the dream. A 14 year old U17 Champion was unheard of. Contrary to what the name might suggest, most of the winners of the U17 championship turned out to be 17 years old themselves or thereabouts- a product of rules that did not truly make sense. The only requirement to participate was that one had to be below 17 years of age at the time the venue of the tournament was announced which tended to happen at the end of the previous tournament. 

Speaking of…. "Have you sorted out your registration for the tournament? You still have up until the new year to sort it out but it's always better to be early with these things" He asked. 

"I'm on it. I owled to inquire about the registration requirements and it turns out I just need to register an official sponsor of some sort and play ten galleons" His protege replied while going through the wand movements for the _abverto_ shield. 

"No. You don't need a sponsor. You only need one when you can't afford to pay the ten galleon fee" He replied instantly. It was a problem he himself had run across. Even back then, Hogwarts had had the policy of never sponsoring students to take part in the tournament. He hadn't had the money himself and had to secure a sponsorship from his father's side of the family. It had been humiliating, kneeling before them and essentially grovelling for their help, but that had proven worth it in the end. He'd paid back their investment and cut ties from a position of strength. He still thought back to the day he returned with their gold with pride. His student didn't need to worry about such, he estimated with a look at Lily's boy's clothes. Even his exercise clothing was of the highest quality. 

"So I just need to send them the money and my name and that's it?" He asked. 

"You also need to sort out your travel and accommodation. The tournament will take place in Broekzele. They've hosted several duelling tournaments since Grindelwald's fall so there should be no shortage of inns and hotels that will be available for the tournament period. The better ones will be booked ahead of time so it's best if you look into that. To be completely honest, the best way of doing this whole thing is to get an agent on ground to handle it." 

"An agent?" 

"Or a manager. The best duelists have dedicated teams of trainers, researchers, and agents to handle things like this in terms of lead up to the tournament. While you are nowhere near advanced enough to need your own team of researchers to look into your opponents and examine your previous fights, and I am already your trainer, you would be served well by an agent to handle the tedious logistics that comes with international tournaments." He explained. He would not have recommended this to most others at this stage, but the boy had the gold to spend, and also had enough of a burden on his shoulders with the desire to win the tournament on his very first try. 

"We have an hour until breakfast. Draw your wand, Mr Potter" He said and gestured to prepare the classroom for their clash. Harry Potter was an enigma when it came to his magic. He had always been a powerful wizard. The Patronus he had conjured earlier this year had left no doubt in any's mind of that. Even the fact that he was practiced enough in the spell to call forth two different corporeal forms was something to be said. While the patronus changes form when its user goes through significant change, what is often unsaid along with that fact is that when one's form changed, the spell became much harder to cast. Almost twice as difficult, he had read. And yet the papers showed the boy achieving it with no strain. 

Filius took his stance and waited for the boy to reciprocate. "A wider base is more useful for when you intend to begin with powerful spells and hunker down in shields when attacked. Your legs should be closer together, but not too close so you trip over them when trying to dodge" He said, correcting the stance. 

"Having the standard's duelist shield on your offhand is the only reason to have it out in the open the way it is now. If you don't drop it to the side or place it behind your back, you risk being struck by an inopportune spell" he said next, correcting that mistake and humming appreciatively when the boy's hand disappeared behind his back. 

"Good. Begin" Filius finally said, seeing no more egregious mistakes in his protege's form. He allowed the boy go first even if to his eyes it looked like he was wading through jelly as he forced his wand through the motions of the spell. Two silvery lances of magic. Shield breakers. A crafty first choice. They were designed to punch through most forms of magical protection and not much else. But they did have the effect of stunning magical upon contact if they didn't spend their energy on a shield first, so they were best off avoiding. 

He pushed one leg backwards and turned to the side, allowing both spells to sail right past him. He returned fire with half a dozen tripping jinxes in half as many seconds, and credit to his reactions, he managed to deflect half pf them and ducked to avoid the rest. He took a deep breath, and took off the metaphorical gloves. 

XXXXXX- HE WITH WAY TOO MANY NAMES 

The Hogwarts Headmaster stared at the duel as it unfolded before him. Filius Flitwick was a good man, better than most, but he had an independent streak a kilometre wide. It might have been an affectation of his father's race who were thoroughly individualistic in nature. Normally, he would not have minded. The Charms Master never worked against him. Or at least, he hadn't risked that until now. 

'All information regarding Harry Potter is to be brought to me on the first instance" he'd ordered after the boy took up residence in the Chamber of Secrets. And yet, Filius had been giving the boy lessons for days before seeing it fit to inform him. He watched them trade spells as young Harry began a series of complex transfigurations that Dumbledore knew were beyond the ability of every student and even a few professors. He watched Filius weave through obstacle after obstacle until the duel reached its natural end and then when it was over, he apparated to his office, careful to leave Flitwick's wards undisturbed. 

When he arrived, he went straight to the pensive and dove in. This was a memory from decades ago. One of the few times that Merrythought had requested his help in her classroom as they covered transfiguration in battle. The students had been allowed to duel in pairs and watching a young Tom Riddle trade spells with Alexander Rosier nearly brought his old heart to a still. Where Riddle stood, his mind could superimpose an image of Harry Potter, and their movements were nearly identical. The same bias to grand gestures with their wands, the same way their eyes flickered to where their spells would land seconds before the spells were even fired, the same over-exaggerated twirl of the wrist after each transfiguration. 

A/N: As always, the next two chapters are up on patreon(www.patreon.com/Oghenevwogaga). There's a handy little December discount on both monthly and annual plans. If you just want to read complete chapters and not my work in real-time, then feel free to purchase this story as a collection on my pa-treon page- nice way to support this story, and me while you're at it. Enjoy!