A.N. So, A Harry Potter Familiar of Zero crossover. I've been toying for this idea for some time. A couple of things off the bat. I don't really like how I wrote it, but I did so to remove ties to his previous world and so people don't immediately assume Harry Potter will start a revolution to induce the wonderful power of democracy to Halkeginia. Also avoided the whole summoned as a schoolboy routine that is popular, to make him weak entering the whatever world it is. As always, modifying some things to try and 'mesh', noticeably the last sentence. Will go into that later. Also, I write this knowing how it begins, with how some things play out, and not particularly seeing how it ends, trying to string it together. So don't expect anything amazing. I'll probably screw up trying to make character interactions work, still don't think I'm particularly good (read 'right bollocks') at it, but I'm trying.

Oh, one other thing. I'll probably say it when I make updates on other stories (actually feel like writing for once) but I have no intention of bashing characters. Arseholes are still Arseholes, but say I had Dumbledore in a story, manipulative maybe, but paper thin schemes for controlling the entire world not caring about anyone, no. So, pre-emptively, Louise will not be a super bitch whipping people at the drop of a hat etc, etc.

I'm sure it's over said, but I appreciate any reviews since they may help me, but something like 'good fic, update soon' or 'Crap, don't bother', while a boost/hit to my ego, isn't particularly helpful.

Harry Potter was bored. It had been decades since he had defeated Voldemort, and he was sat in his home, alone, watching some crappy thing on the television. In the aftermath of Voldemort's defeat he had hooked up with Ginny again, but she, likely at the behest of her mother, had almost immediately started planning their wedding. He had tried to convince her that he wasn't getting married until he was at least 30 and, well… it wasn't taken well. It had strained his relationship with all the remaining Weasleys. Sometime later he had refused to support one of Hermione's crusades for justice or whatever. She had got quite loud about it and it had gotten in the paper. His support (or lack thereof) had destroyed her chances of success before she even started. She hadn't spoken to him since. He didn't regret his choice. While promoting equality for all was a noble goal, Harry had no desire to fight for such a meaningless thing. After all he could hear it. No, he removed those thoughts from his mind. It was like Dumbledore told him, disregard them and force yourself to not hear them. Paying them any mind would lead to the same madness that claimed Voldemort. Which led him back to where he started. The Ministry was worthless. The world would be better if, after removing Voldemort he had taken control of Britain himself. Something that ran directly counter to equality. He could see the signs, Dark Lords were rising again. He had dealt with one recently and it had cost him his job. He admitted to himself that anyone else would have been arrested, but they hadn't dared, with him.

The justice that Hermione believed in could only be upheld with superior power, without it, it was empty bleating from worthless sheep.

No. He didn't believe in equality and justice, and even after all they'd been through that had been enough for Hermione to end their friendship.

After the war, they had tried to shepherd him into being an auror. He hadn't obliged them, and instead became a healer. Even if it was pointless, he still wanted to help people. It had been a complicated feeling. Of course, many came to think his combat ability lacking as a result of that choice. He had dissuaded them of that notion with a good thrashing. Some of those fools were still used as an example of why people shouldn't cross him. His possession of the deathly hollows was widely known, and likely contributed as to why people risked their lives to try and kill him. Greed and lust for power were powerful things.

However such people included ingeniously clever people. His employment as a healer had recently come to an end. There had been inferi discovered at a remote magical village (Hogsmeade wasn't the only magical settlement, just the most prestigious). He and a few others had been dispatched to deal with the injuries, but the victims had been infected, turning into inferi themselves. Honestly it was like one of those muggle zombie films.

After he had destroyed the closest ones, he had immediately decided to raze the entire village, ensuring the infection could not spread. He hadn't particularly wanted to, there were many who hadn't been infected, but having a young child lunge and try to rip your throat out can work wonders on the seeing the necessity of such ruthlessness. The ministry and the public hadn't agreed. The end result was he was stripped of his license and disgraced. Well, he hadn't much cared for public opinion anyway.

That led to why he was bored. He had no job to consume his time, no friends to spend time with, at least none in the current public climate.

He suddenly got to his feet, swiping his hand, covered by a thick glove, through his hair, sweeping it back, a useful wandless spell to be sure, leaving his famous scar on display. He'd probably go visit Dudley. They had mended their relationship since they were children, and while he'd retired from the world of professional boxing, Dudley was always up for a match. Probably because Harry still looked great, like he was mid-twenties, albeit with some grey splashed in his hair, while Dudley really was getting on in years, and owning Harry in the ring made him feel good about himself.

He threw on his robe, a custom made one that could be mistaken for a long coat, and his satchel containing his medical supplies (he went nowhere without them) and apparated to a point near Dudley's home.

Unfortunately, power called to power, destiny called to destiny, and at that moment, someone was opening a portal to beg for aid, and even if he wasn't aware of it, he would answer that call.

….

Harry frowned. He had not been intending to go to any magical location. He looked around. Unless he was much mistaken these kids were wearing a uniform, albeit one he was unfamiliar with. That would make the older guy there a teacher. He tried to apparate again. It didn't work. His frown deepened. He could apparate half way round the world. Or something, it involved going through the world, but avoiding the centre, or something. It was a shame Hermione wouldn't explain it to him.

He looked in time to see a pink haired girl walk up to him.

"You should be honoured. A commoner usually wouldn't get something like this in a lifetime."

After that she chanted something. He caught something about a familiar before trying to kiss him. He decided to stop it right there.

"Hold up, I don't kiss pretty girls until at least after we've exchanged names." He looked around at the older man "would you mind explaining what's going on here?"

He sensed that the pink haired girl was feeling embarrassed or annoyed (he wasn't willing to go to the depths of dark magic that let men understand the hearts of girls after all, he joked to himself) and that the other kids seemed to be laughing at her, but he dismissed it as not involving him.

The man adjusted his glasses "Of course, Miss Valliere summoned you using the springtime summoning ritual, and is going to bind you as her familiar."

Yeah, that wasn't happening. He voiced that thought. "That isn't happening."

The girl's cheeks reddened further. A little more and she'd be Weasley red he mused.

The man frowned, "That would be irregular. Each student can only use the ritual to summon a familiar successfully once, and she summoned you. Of course, I've never heard of a summon refusing the binding. Are you sure you won't accept it?"

"Of course."

The man furrowed his brow. Harry thought he might be considering forcing the issue, but decided against it. "I'll have to do some research into what this means, and then discuss this with the other professors. If you'd join me, mister ?"

Harry paused before answering. Based on what he saw, using his name 'Potter' would likely cause the misunderstanding of him being a potter, which if the society was anything like back home, would weaken his position in whatever discussions would come regarding this matter. And so "Black, Harry Black. Lead on Mister…"

"Ah, where are my manners, Colbert, Jean Colbert."

"What about me? What do I do" Harry looked around at the girl who had suddenly shouted out.

"Miss Valliere, you'll have to wait until this matter has been discussed with the Headmaster. Once it's been discussed you may be allowed to try again, so you'll just have to be patient. Alright, if you'd all like to return to your rooms, this lesson is over."

With that all the students began to leave. Including the pink haired girl.

"Mister Colbert, wouldn't it be better if my, let's say, summoner was involved in the discussions?"

He paused. "well getting her input certainly wouldn't hurt matters, I suppose. Miss Valliere if you would like to join us?"

The girl hesitated, before giving a quick 'yes sir' and following along.

….

Harry sat across from a man that had to be at least as old as Dumbledore. That was his thought when he first saw the man. The fact that the man was also the headmaster of a school for magic made him wonder if the universe had decided to break out the leather and whips again. Metaphorically, of course.

"So you want me to become girly's familiar" he clarified.

"That is correct" the old man agreed.

"No."

"I see." The two of them sat staring at each other for several minutes. The other that occupants of the room sat still, not daring to speak and interrupt the battle of wills taking place.

The old man eventually gave in "Do you have any other options? Your clothes come from nowhere I recognise, and you certainly don't seem to have the supplies to live on. I would hazard a guess that you have no one in this country that would be willing to aid you, and no marketable skills to get by with."

"Heh, you underestimate me old man." He put his hand into his robe, drawing out a pair of panties with a smirk. "Counter offer, you put me up with a room here until I figure out what to do, and you can have these panties your mouse there was peeping at."

The woman in questions eyes widened before she lunged across the table at him, unintentionally giving the old man quite a view. Harry effortlessly managed to get out of his chair and avoid her grasp, twirling the underwear around his fingers.

Professor Colbert blushed and looked aside, and the girl, Valliere blushed and spluttered and the old man…

"Deal!" The old man agreed instantly reaching out and snatching the underwear and hiding it in his robes.

"Great" Harry smiled, watching the old man being wrestled to the floor by the woman trying to get her underwear back.

"Wait! What about me? Will I get to try and summon a new familiar?" The girl asked with what seemed to be a minor case of panic.

"Unfortunately you have successfully cast the spell 'Summon familiar' and cannot try again, regardless of the person in question not wishing to become a familiar. You will just have to try and convince this fine gentleman here to reconsider, or simply not have a familiar." The old man crushed her hopes uncaring of the fact that he had lost his new treasure.

"Like I'd want a familiar with such a questionable skill!"

"Alas the decision has been made Miss Valliere. Now if that is all? I shall have a maid prepare a room for our new visitor."

The girl looked down, so that no one could see her face. Harry noticed that she was trembling. While he may not be able to judge a maidens heart, he could at least tell the fact that she wasn't trembling in anger, and that there were a couple of tears staining her uniform. "If that is all, I shall be retiring to my rom." The girl said in a level voice. Without waiting for a reply the girl turned and left the room.

Harry watched her go, with an uncomfortable feeling in his chest. Ah. This was the guilt he felt when he made a girl cry. He hadn't felt it for a while.

….

Osman sat at his desk, staring at the door that Harry Black had just been led out of by a maid named… well, there was no real reason to remember the names of the servants. It was regrettable but he was getting old, he didn't have the memory he used to.

"Was that wise?" Jean asked.

Osman considered it. "Possibly." He answered. "He wasn't going to budge on that issue by anything we do. Perhaps young Valliere can change his mind, but if not… It is important he be here. I'm guessing you didn't feel it, but he was strong. His magic didn't feel like anything I recognise."

"When did he use magic?" Jean asked, curious.

"It was how he got the panties." The headmaster said. "It was no magic I know of, and I quickly checked them while I had them. Not only is summoning a human unheard of, said human can use an unknown magic. That he did it was a clear showing that he possessed such power, a show to make us wary of him. There's no telling what he is capable of, or what he will do. It is regrettable, but we cannot allow him to go and do as he pleases. He must be watched, and there are startlingly few I can trust such a task to. Imagine if certain parties got such talents under their control. Honestly, it was a brilliant move."

"What of Miss Valliere then? She doesn't have a familiar. Will she be sent from the school?"

"No, that would undoubtedly bring a scary monster down on us" the old man joked "and besides, she managed the summon spell, so there are no grounds to dismiss her. That is the stance I am going for. And until the particular of this summoning are figured out, Valliere cannot be allowed to try again."

Osmand sighed tiredly. "Be careful Jean, I am getting a troubling feeling. I don't know what will happen, but it feels like unstoppable events have been set in motion."

….

Harry smirked to himself as he followed the maid. He couldn't believe he'd managed to secure lodging for that secretary's panties. Honestly, he'd intended it as a joke, expecting a reprimand. Thank God for dirty old men he supposed.

He noticed the maid shooting him glances. Deciding to make some friends among the serving staff, he spoke up, throwing a discrete charm to make someone comfortable talking, thank you Dumbledore "Crazy day, huh? Well it has been for me, but I suppose for you it's been a rather normal one, miss…?"

The maid stumbled "Ah, yes. Siesta, my names Siesta. Is it true? That you were summoned by a noble as a familiar?"

He nodded "that's right, some young girl, Valliere or some such yoinked me as I was going to visit my cousin." At her confusion he clarified "Yoinked, it means grabbed, or rather in this case, summoned." He remembered seeing the Girl hiding her tears. "Anything you can tell me about her?"

Siesta looked a little uncomfortable. One more discrete charm later "She's alright, for a noble I suppose. But she's looked down on for not being able to cast magic properly, the other students call her Louise the Zero. Occasionally she has bad moods and will shout at us, but that's all really."

"Ohhh, I see." He felt bad for the girl, not enough to be bound to her, but she was hoping to prove her worth. A feeling he was familiar with. The hat's words came back to him. Maybe there was something to the 'summoning the best match' the old man was going on about. He knew something about teaching after all. Well, if he could figure out whatever magic they used around here, or if they could use his.

"This is the room you've been assigned" Siesta said, gesturing at a door they had arrived at. "If that will be all?"

"For now, at least. I'm new here, I've not even heard of this 'Tristain' we are apparently in before."

The girls eyes widened "SO where are you from then? Most lands would at least have heard of Tristain."

Harry laughed "Who knows. I was getting bored of home anyway. Seeing a new place sounds like fun. On that note" He flashed her a smile, his teeth seeming to gleam (At least he'd learned something from Professor Lockheart) "I'd love it if you would show me around sometime."

Siesta, somewhat flustered agreed before rushing off. He chuckled to himself. Dudley had always been annoyed that he could charm girls less than half his age. The benefits of a youthful appearance he supposed, as well as his natural charm. He turned and entered the room. He was honestly surprised that it looked at least as comfortable as his room back when he was in school.

He closed his eyes. Ignoring, as always the whispers at the back of his mind, urging him to unleash his power, to reduce the world to nothing. Ignoring the whispers of the Void.