AN: As I am still undecided what I intend to do with my two original HP/Overlord crossovers. (I am strongly considering removing all but the first two chapters of HPatFA for example) To try and get myself out of this rut I decided to attempt York Lane's Potter's Bloodfallen challenge, albeit with some major modifications. As a note I have swapped the challenge's original intended character of Shalltear for another Floor Guardian that I felt was much more fitting for Harry's role in Nazarick.

1. The first chapter must be an introductory chapter like his. (Accepted)
2. Shalltear is the child who lived. (Rejected and twisted) (You will see why eventually.)
3. You can make this a wrong child who lived story. (Twsted. While Harry may not be the boy who lived he is the one the prophecy is about.)
4. If her parents are alive she does not grow fond of them or like them in any way, they are not family to her. (Rejected)
5. Parents can be alive. (Accepted)
6. Bad Dumbledore (Rejected with a twist. My Dumbledore is very manipulative, but being manipulative and making harsh choices does not make one an evil person. My Dumbledore is simply a man doing what is necessary in a wartime situation.)
7. Have fun. (Accepted! )

I won't say anything more other than that I will probably be mangling a few facts from both lores but I like to think I am going to get most of it right. Criticism and reviews as always are adored. And of course I own neither Harry Potter or Overlord in any way, shape, or form. Anyways without any further ado here it is.

Yggdrasil - Helheim - The Great Tomb of Nazarick - Sixth Floor - Forest Clearing

In a clearing amidst a rain forest that was alive with the sounds of magic and construction was a most curious sight. A pink slime was at work, its appendages formed of slime just like the rest of its body were moving and waving as it scrolled and controlled menu screens floating in the air before it. As it moved its slime appendages it hummed to itself, its voice, unlike how many would perceive it's body, absolutely divine sounding to listen to. Given that in the real world she was a voice actress the slime that called herself Bukubukuchagama in this world and place was quietly talking to herself.

"Create an NPC to command the Sixth floor's defenses. What to do what what to do." She murmured almost absentmindedly to herself. "Should I make a warrior? No I think someone said that the floor before this was going to have a warrior boss. If that's the case the best thing would be something else. A spell caster would be good but what kind." Stopping for a moment the slime looked around at the jungle forest that was being grown all around her, even taking a moment to look upwards at the sky that a fellow guild-mate was diligently creating. "It is lovely here. It would be a shame not to use this as inspiration. Hmmm... Oh I know. A Druid." Tapping a screen she pulled up the NPC creation menu. When the menu first showed up and she initiated the creation process a human boy no more than six or maybe eight years of age appeared standing before her.

If the slime could have blinked she would have. But this was her first NPC creation. "How impressive. He looks rather lifelike." She said as she looked at the perfectly still human boy with black hair and green eyes. "There's something about that shade of green though." The color to her wasn't the peaceful color of grass and life, but a slightly different shade of green for reasons that she didn't know, sent a shiver of fear through her. Not understanding her own reaction the slime's head wiggled from side to side as the Player shook away her unexplained feeling. Before going any further she adjusted the NPC creation menu shifting the NPC's eye color. But the strangest thing happened. While the right eye changed to whatever color she indicated, the left eye didn't change at all. The player couldn't help but frown but suddenly stopped manipulating the colors when the right eye shifted to the shade of blue like the sky.

Though that green still gave her a faint sense of unease, the pairing of green and blue was so perfect in her mind for what a druid was supposed to be that she just stopped and starred for a few moments before smiling. "Maybe this is meant to be." She muttered to herself before humming she set about the character creation process again. She knew she intended to create a pure caster but she needed to balance levels carefully. She herself was a Heteromorph and powerful for it but she only had one hundred levels to use on this character. Rather than waste levels on a different race she choose to make her NPC an elf. An elf even though it did not have any racial levels to gain, would still have an affinity as a druid and would strengthen the magic it would be capable of wielding.

Setting the race to dark elf she stopped and stared as the black hair became blond and as pointy ears appeared. The NPC was still the same age, probably eight or so years old by human measurements, but by an elf's age it could be sixty or seventy years old and still look the same. There was something precious about the elf boy now standing perfectly still before her. Of course it didn't breath or blink. It was an NPC, not a living creature in the real world but that didn't stop even now, the slime from marveling at how lifelike it appeared.

Bukubukuchagama continued to spend the better part of an hour deciding the NPC's levels. There were so many options to choose from and while she knew she wanted a pure druid caster, even with those criteria eliminating many many options, there were still so many to pick from. Finally though she managed to settle on its classes. With the base structure of the NPC decided it was now time to equip it and set its programed 'backstory' as many of the guild called the programing. For this the slime used her own personal inventory to equip the NPC. Of course there was a base set of gear that an NPC could use if nothing was given to it. But this was to be the Sixth Floor Guardian of Nazarick. Ordinary gear simply would not do. It wasn't until she was sorting through her inventory though that Bukubukuchagama realized that she didn't have any clothes fit for a boy or male at all. In fact because she was a slime and didn't wear armor or clothes of any kind, the only outfit she had in her inventory at all was a looted outfit that had been dropped by a boss three days previously. Sadly it was a girl's outfit. But the stats alone were enough that despite the perversion that normally only her Brother indulged in, she put it on the NPC. After all it wasn't like it was a living being or anything.

Once the NPC though was standing there in its new outfit, the skirt barely coming down to it's mid-thighs and stockings coming almost all the way up to meet it, as well as blue sleeves under a white vest she stopped. Bukubukuchagama prided herself on not being a pervert like her unrepentant brother. In fact she delighted in ruining his perverse pleasure whenever she could. But there was something unexpectely feminine about how the elf boy looked. If she didn't know the gender were still set to male she would have assumed he was a girl after all. Smiling for a moment she decided to not to change the outfit later on. Moving back into her inventory she removed items fit for a druid she'd been waiting to sell. Luckily she had a good inventory of gear. Boots, a necklace, an actual God Tier staff called Shadow of Ydrassil.

The staff was immensely powerful but was restricted to elf druids for use. No other combination of races and classes could wield it. Bukubukuchagama hadn't even been thinking about it when she had created her NPC but now that she had found it sitting in her inventory she felt as if fate and destiny were at work now. It had been whim that she created the NPC this way and yet she had gotten as a drop in a boss raid, this staff not even a month before. Such a powerful staff would bring a massive amount of gold but she hadn't sold it because it would have to be someone outside the guild and could easily have been used against Ainz Ooal Gown's members. Rather than let such a powerful magical weapon into enemy hands she had kept it. Now though it had a place and a purpose.

The slime continued to work through her inventory giving the elf NPC items it would need to fulfill its purpose. When it was done Bukubukuchagama turned her attention back to the NPC creation menu and continued fiddling with the settings. In the NPC's settings she assigned all the important data but still had a bit of room. Eyeing the perfectly still elf child she wondered what he would be like if he were real. In her heart she just knew he would love to read, but would be a quiet timid type of person. The kind of person that would rather be around animals out in nature, or would be tending to plants, than rather be running around playing sports with other children, or being loud and noisy and playing pranks. In a straight forward explanation. This elf was not her brother. Knowing instinctively the elf's personality, if he had one she used the remaining setting space to set the backstory. In the end all that was left now was the NPC's name. Surprisingly this took the longest time but in the end between the blue dragon scale hide of the boy's shirt and right eye, contrasted against the left green eye, and blond hair like a golden sun, she knew. This boy reminded her of a plant amidst water. And so she borrowed from the Itallian language to name him.

Mare Bello Fiore.

A final tap of the button on the menu and there was a shimmer of light for a moment as if a magic spell had been cast. Curiously turning her slime body to look and see if anyone from the guild was playing a trick on her, she looked a few moments later to see the NPC standing there. Her pink slime body wiggled as the Player did a little dance of success at having created an NPC. And a powerful one at that! She knew some of the other Floor Guardians were already done, her foolish idiot brother's vampire was certainly dangerous in a fight but her brother had told her, the vampire's stats and looking at the stat sheet now Bukubukuchagama almost couldn't believe it that the NPC was so powerful. It's stats were a match for any of the members of the guild and she knew she'd struck gold in creating the elf. Still she went still as she studied her creation. She inherently knew that the NPC wasn't real. That it never had been and never knew it would be real. But those mismatched green and blue eyes looked... lonely. Frowning Bukubukuchagama moved away to go find a guild member. She had used up her allotted levels in creating the elf NPC FLoor Guardian. She would need to talk to the others about sharing some levels with her to allow her to make a companion NPC. Somehow she just knew that if this elf boy were real. He would be lonely without his older sibling around.

Bukubukuchagama never noticed a single impossibility occur as she moved away. From that hauntingly green left eye ran a single tear.

Yggdrasil - Helheim - The Great Tomb of Nazarick - Sixth Floor - Mare's Forest Clearing
Three days later.

It wasn't until the three days later that the shape of the pink slime made its way back to the forest clearing where it had left the NPC Floor Guardian. Bukubukuchagama had been surprised when she talked to the guild leader Momonga about who hadn't used up their aloted NPC levels and might be willing to part with a few levels she could use to create another NPC. The surprise came because as the Guild Leader he had access to statistics for the guild Dungeon and he had assumed she hadn't made her NPC yet because they were still a hundred levels under budget and all the other intended level one hundred NPC's had been created along with most of the other NPC's. Certainly so many that there was no way for them to be mysteriously under their guild base NPC level limit to that amount. Confusion had abounded until another of the guild members had suggested that perhaps the answer lay with their newest World Item, the Throne of Kings. Sanity and rationality quickly resumed as the idea circulated among arguing and confused members of the guild. After all the idea of a glitch was worrisome. While right now it might be good, having a free level one hundred NPC, the roster of NPC's showed Mare Bello Fiore, but it did not show him as the Sixth Floor Guardian or as a cost drain on the guild's resources. However the idea that his oddity resulted from the Throne of Kings made sense. While the Throne had other effects that had been noticed, most items did not come with instruction manuals, and the idea that a World Item might be the reason eased many worries that 'those shitty Devs' wouldn't do something to fix the 'glitch' that was Bukubukuchagama's creation at the worst possible time like if Nazarick was under attack.

Combined with the fact that Mare apparently wasn't registering as the Sixth Floor Floor Guardian it was decided the pink slime would create a second level one hundred NPC that would be the Floor Guardian and make the Sixth Floor all the deadlier. The next few days had been spent gathering items. Bukubukuchagama knew she had gotten extremely lucky how her inventory had just so happened to have a perfect set of items for Mare. But having just gone through her inventory she knew that she wouldn't have the same luck again, particularly as she'd decided to give Mare a big sister to look after him and keep him out of trouble just the way she did with her pervert featherbrained brother.

Now though she was ready to create a Floor Guardian. But before she would do so she took one moment to edit her first and original creation's settings. Just because he couldn't officially become the Floor Guardian, didn't mean she wouldn't recognize her original intent. She included a few more lines of description for background that stated that he shared the duties of being the Sixth Floor Guardian with his big sister. Smiling she turned and moved a little ways to the side and opening the NPC creation window she got to work on creating the NPC she had been envisioning as Mare's big sister. She noticed that this time rather than having the NPC standing there in front of her on the grass it was just a displayed screen. But after playing with the settings for a little bit she realized that the glitch with Mare's eye color wasn't happening like before and just assumed those Shitty Dev's were just doing their jobs for once. Paying it no more mind she set to work in creating her next NPC. Unlike before Bukubukuchagama already had most of the idea in her head in how she wanted to make her new NPC. She was making Mare a sister, that was already decided. But she wouldn't be the same as him, it wouldn't be right after all and the floor would be more dangerous the more varied and versatile its defenders were.

So rather than a powerful druid she had chosen a Ranger and Beast Master instead. Where Mare was a powerful caster that ranked only a little bit below her fellow guild mate Ulbert Alain Odle who was one of the most deadly magic caster Players in the entire game. The pink slime's head bobbed as she shook her head at the thought of just how powerful Mare really was but just sighed as it was all due to the World Item sitting in the guild's throne room. Getting back to work she continued at it. The same mismatched eyes were the start though she flipped them around so that the green and the blue were opposites from Mare. Working her way through the character creation menu she was much quicker this time as she'd already decided many things and only had to tweak and refine a few things as she worked so that they were optimized as much as possible.

When it was finished a second dark elf child stood perfectly still next to Mare. Anyone who looked at the two would see the resemblance of siblings. And indeed there was a crowd as more than a few members of the guild had come to see the NPC that had caused so much confusion just a few days before. Standing at the center was the guild master himself, her friend Momonga, her brother ever the pervert seemed to be leering at Mare, no doubt not realizing that Mare was really a boy. She suspected even that wouldn't be enough to stop her brother from fantasizing about the elf boy given his depraved nature. Frowning she made a mental note to take him to task the next time they were together in the real world. It wouldn't do to let his perversion run rampant anymore than it already did. That was what big sisters were for after all, to keep their foolish little brothers in line. She smiled a little as her pink head turned and she looked at the pair of NPC's while the gathered guild members chattered and admired the pair of NPC's. Atleast Mare had a big sister to keep him in line if he ever made mistakes or was going to do something stupid. If they were real Bukubukuchagama knew that the both of them would love each other like siblings should and that both would protect each other from anything, but that Aura would go to the very ends of the earth and beyond if needed to make sure that Mare was safe and stayed out of trouble.

Turning the pink slime moved away and joined her chattering guild mates leaving the pair of sibling NPC's where they were.

Yggdrasil - Helheim - The Great Tomb of Nazarick - Sixth Floor - Aura and Mare's Tree Home
Five Years Later - The Final Day of Yggdrasil - Eight hours before the servers shut down.

The Pink Slime moved around the inner area of the Tree that had been created to serve as her NPC children's home. Like many of the other guild members she had spent time and effort, as well as resources continuing to tend to her creations. While they all knew that the NPC's didn't require homes, or anything really, they were just data and programing after all. The Guildmembers of Ainz Ooal Gown didn't look at their creations that way. Each of the members of the guild had been involved in the creation of the Unconquerable Guild Dungeon, The Great Tomb of Nazarick. They had stood with pride the day they had defeated the invasion of 1500 enemy players. And while yes it had been the Eighth Floor that had finally stopped the invaders she had watched with pride as the NPC's that she regarded as her children, had laid waste to hundreds of invading players before falling. Sadly Aura the sister she had created for Mare had fallen first. She just wasn't as strong, neither the quirk of strength that Mare benefited from presumably courtesy of the Throne of Kings, nor whatever other hidden benefits it gave the elf boy, had extended to the female elf. And in truth Aura's deadliness came from her many beasts rather than the ranger herself. In single one on one combat the elf ranger was pitifully weak by the standards of a level 100 of any kind. But surrounded by her beasts that Bukubukuchagama and others had carefully selected, she was as strong as two and a half level 100 NPC's because of her abilities to buff and strengthen her beasts.

The slime and the gathered members of the guild had watched that day as Aura had fallen but Mare had continued to fight on. It had been astounding as nearly fifty players had fallen to Mare even after Aura fell. And while there were other factors such as the remaining beasts belonging to Aura, as well as the pair of Platinum Dragons that served Mare. All the guild had been speechless as they had watched what should have been impossible. Many had thought the invasion would falter at the sixth level but eventually they had watched as sheer numbers alone had brought the elf druid down. By comparison the seventh level put up not even a quarter of the fight that the level before it did and it was only on the Eighth level that the last two hundred of the invaders finally met their match when the monsters of the Eighth Floor fell upon their enemies.

Confusion and surprise had reigned again in the following day. Like normal NPC's Aura had required vast sums of gold to resurrect, Mare however had not. When the guild members had returned to play the following morning, those who investigated the Sixth Level as part of the clean up process had found the NPC alive again standing in the exact where he had fallen in the Coliseum on the Sixth Floor. He was perfectly still as always, this was just an NPC. Apart from the resurrection nothing else was amiss. And in the end everyone just assumed that the World Item assumed to be responsible for all the quirks surrounding Mare, was responsible once again.

That had been years ago now for both NPC and Player alike. The cute pink slime was spending her first time in the game in almost two years. She wouldn't have returned at all, life was so busy in her work and with many of the guild members gone the game had lost its allure for her. But she couldn't reject Momonga's message for one final get together. She had spent an hour talking to her fellow player and friend before making her way down to the Sixth Level. She wouldn't stay until the end of the servers. In truth she hadn't even intended to spend the hour she had spent talking to Momonga. It had been her plan to be on for maybe twenty minutes, thirty tops. But nostalgia had reared its head and she'd spent the hour remembering the old days of years before with the undead guild leader who had continued to play on and had acted like a caretaker to the mausoleum to the past that Nazarick had seemed to become.

Even though she'd spent more time than she'd planned or even wanted to, she wasn't just going to leave though. She wanted to see her creations once last time. Particularly Mare. She loved both, and thought of them as her children. But though she would never admit it to anyone, Mare had always held a special place in her heart. He had been her first creation, and in many ways her first child. Like any mother she had created him, her actions had given birth to him and as much life as the game would allow had been the results of her actions and choices. He was her child as she was his mother. Standing in one of the rooms of the tree home the pair 'lived' in she looked around smiling to herself. A kitchen for NPC's that did not eat. Beds for those that did not sleep. Even though an NPC would never read she had filled Mare's room with shelves of books just as she had filled Aura's room with all the items and trinkets that she would keep in her room if she were real. In some ways some might say that she had poured her heart and soul into the pair. And it was with many emotions, chief among them being pride, and sadness, that she looked over her creations one final time. She lingered, even going so far as to move her pink slime body to each of her creation and pressing her 'head' to the forehead of each as she gave them a kiss goodbye before she departed for her final time.

AN: My next chapter will deal with the HP world and the aftermath of his disappearance up through his return. I hope you all enjoy this and I look forward to reading your reviews. Until next time.