Deep within the last floor of the Necropolis Dungeon, a large 10 meter orb hovered silently. Stone and earth surrounded it, being very slowly dug downward. It was an extremely slow and time consuming process, as the stone was reformed and replaced with a much more durable version imbued with the orb's mana. In doing so, the stone gained new properties, such as self regeneration and extreme hardening. With each new floor, the orb's technique improved ever so slightly, making every new floor better than the last.
This orb was the dungeon's core. She was the mother of all the monsters that roamed the dungeon, managing multiple operations simultaneously to ensure the dungeon ran at peak performance. As for why a genderless being like a dungeon core was referred to with feminine pronouns and as "mother" by all her undead, it was simply because she preferred to be addressed that way by her monsters.
But the orb's main attention wasn't on the maze forming beneath her; she could manage that in her sleep, if she could even sleep in the first place. What the orb was actually focused on was the situation occurring many floors above her. One of the effects of the transformed stone was that she could spread her senses through them and observe what was happening as if she were right there.
It was maddening for the dungeon core that the two humans who had stolen the void root months ago were using the 21st floor as their personal training ground. That void root was the fifth one she had tried cultivating as a means to accelerate her growth by absorbing its energy. Though inefficient to cultivate a plant using her energy only to absorb it later, it was the only option available to her since the mana she usually absorbed from the environment was being siphoned off to maintain the walls of the city surrounding her. But every time she grew a new one, someone swooped in and stole it. At first, she considered herself unlucky because the void root's growth required it to be near the surface to absorb various other energies she couldn't provide. However, as it happened century after century, her tolerance began to wear out. She wasn't able to pay attention to it around the clock, as she had to manage an entire dungeon, and it only took a brief moment for some adventure to appear and take it before she could move it.
Many times, she considered collapsing the entire room on the two latest thieves for revenge but held back because of the rules her creator, Proteus, had put in place. There were many rules, but three were the most important and took priority above all others.
The first was to let the races of the world use their dungeons as places to train and improve. The second was to create a safe area at the start of every floor to give people a place to rest and recover. Proteus didn't want the dungeons to be so brutal that few could survive; they should be challenging but not excessively so. The final rule was to keep their monsters from leaving the dungeon and entering the outside world without his permission. Monsters were also forbidden from crossing the stairs between floors to prevent imbalances within the dungeons.
These rules were established after the war against the Outer Gods when dungeons lost their purpose as a near infinite supply of troops for the front lines. Instead of serving as barracks for endless troops, they were transformed into the dungeons seen today, designed to train the new generation to be prepared against future threats. Just as dungeon monsters obeyed the will of the dungeon, the dungeons obeyed the will of Proteus. They did exactly as he commanded and adapted to better suit their new purpose.
The transition to their new role as the world's training centers wasn't difficult. As creations of Proteus, the God of Transformation, dungeons were able to easily change themselves to better suit their new purpose. It was even better for them, as they could focus on developing and improving the law techniques they used to manage their dungeons.
But what bothered the dungeon core was that, despite all the options available to her, she couldn't use any of them without risking going against her creator's will. Collapsing the entire floor or sending all the monsters from the floor after the two would have easily ended their lives. Within the rules, there were ways to kill those she wanted to, but against that duo, it was useless. She created multiple monster houses throughout the floors, hoping they would run into at least one of them, but not only did both have stealth skills, one could see the undead from far away and took detours around them.
When that hateful duo encountered a Zomest, the dungeon core knew there was no way this rare creation of hers would defeat them, but just as the duo was getting ready to kill it, she had a bright idea. If one Zomest couldn't defeat them, what about all of them?
In that moment, she used her authority over the dungeon to bring the Zomests onto the floor, transporting them through the floor itself. Though the rules stated that monsters couldn't use the stairs, they said nothing about moving through the floor.
She knew it was pushing the limits of the rules established by her creator, and though she was unwilling to completely defy his decree, she figured it was fine to bend the rules somewhat, right?
Yet, even after she dropped all four Zomests along with a group of other undead, the two hateful humans managed to evade them and ran away like cowards.
The dungeon core then bent the rules once more, moving the two Zomests that were useless in the chase to the exit so they could make use of their ability. The creature they created together exceeded her expectations; it could perhaps even rival the undead found on the latest floors. Though the Zombeast had some clear downsides, she knew it could easily overpower the two humans, and so she was giddy at the thought of finally killing them and retrieving her void root.
But then she realized something. This creature was a clear A-Rank and directly violated the third rule. The reason creatures couldn't pass to different floors from where they were born was to prevent an A-Rank monster from appearing on the first floor. Though it was brought from another floor, it was too strong for that section of the dungeon and was a clear violation of the rules.
After some consideration, she concluded that it was too much and decided she would rather lose the void root than risk having Proteus hate or punish her. She relayed her will to the Zomest, but instead of the usual obedience, it actually gave her a suggestion.
To simply ask for it back.
If she gave them a chance to return it, all would be well, and the humans could continue exploring normally. If they declined, would Proteus really judge her for bending the rules a little?
She chose to proceed and gave the Zomests permission to ask. Her full attention was on the interaction between the Zomest speaking through the Zombeast and the human. She couldn't understand why the human was being so obtuse and dense about the situation, asking questions and presenting worthless junk her dungeon naturally produced without any effort. It was only when the human declined her offer that she allowed the Zomest to command the Zombeast to kill them—but something unexpected occurred.
The female human standing next to the male turned into a pile of sand as the real female appeared next to the Zomests by the exit and killed them both. The dungeon core visibly shook in surprise at how the woman had escaped her vision. She had been so focused on the talking human that she failed to notice the other one moving behind her back.
Now, she could only watch helplessly as the two humans took the stairs and headed to the boss floor. The Zombeast was the most she could do without actively breaking the rules, so she knew it was over. As for the boss being able to kill them—if being chased by over 20 undead for half an hour wasn't enough to harm them, what could a single boss do? She had bent the rules far more than she should have and wasn't going to make them face ten bosses simultaneously.
If the dungeon core could sigh, she would. She was about to give up and begin the century long process of creating a new void root when she had another idea, inspired by the now dead Zomests. The stone around her, already under her control, began to gather in one spot as she attempted something for the first time. She had no idea if this would work, but if it did, not only would she have another chance to regain her void root within this century, but many more possibilities would be open to her.
Excited by the prospect, she left the two humans to their own devices and started her new project.