The Clatterstep dungeon was of dragonoid type, ninety floors deep, and produced mythril in sufficient quantities to be considered an important national resource. As such the dungeon was well guarded and entrance heavily regulated. Nevertheless a criminal group was able to gain access via tunnelling, avoiding the guarded entrance. This has historically not been something that we watch out for, given the usual dungeon reaction to breaches outside of their official entrance. In this case the dungeon did not react with the expected violence but instead made a deal with the criminals, promising orichalcum in exchange for being fed. This resulted in a spate of missing person incidents in the region, culminating in the destruction of entire villages. That law enforcement was unable to catch them was largely due to the protection offered by the dungeon, which opened and closed new tunnels around the area allowing the criminals to seemingly appear from nowhere. It wasn't until eye witnesses reported the kidnappers wielding orichalcum gear that dungeon involvement was first suspected, at which point high level delvers were sent to investigate and confirmed the growth of the dungeon. Contact with the delvers was lost on floor one hundred and two, at which point the dungeon collapsed its original entrance. Fortunately loss of life in that event was light, as the large part of the guard contingent was stationed outside. At this point the decision was made to terminate the dungeon by tunnelling into the lowest floor from underneath. However, these attempts failed; there was simply no sign of dungeon activity deeper than around 250 metres, where floor ninety should be. Further investigation revealed that the dungeon was using spatial constructs to warp the geometry of its new floors, effectively meaning that they had no exterior surface. The plan was changed to starve the dungeon of mana, tunnelling into floor fifty and putting up shielding to block any mana from the higher floors entering. The lives of many mages were lost in this operation, but it was eventually successful. Recommendations for the future involve keeping watch around the dungeon for new tunnels, and not immediately writing off the possibility of dungeon involvement in large scale criminal cases.

- Report on the Clatterstep dungeon incident

Error: Floors exist that are unregistered. Registering 5 additional floors.

Error: Floors exist below core level. Core must be placed on the lowest floor. Relocating core.

Floors: 100

And that was it: Floor 100. Erryn had moved the monsters from the surface into the dungeon too. Hopefully now all it needed to do was spend a year on its best behaviour, and it would lose the errant tag. Although the way it was using mythril materials from floor twenty four was suspect; Erryn thought the level at which they should be used was far deeper, but it hadn't been particularly literate at the point it had first created mythril and had missed the message. The System did not appear to have a replay button, alas. If it turned out to be a problem Erryn could redo the enchantments in steel, and either remember to refresh them periodically or replace them back with mythril once it had inspected the dungeon point store.

There was also the way Erryn was now hundreds of kilometres of landscape with no traps and barely any monsters, not to mention the human class, instead of... well... being a dungeon. But none of that stuff had displayed the 'already designated as [Errant]' message, so hopefully that was okay. Or else so far from being okay that the System didn't know how to cope with it. Either way worked. It was frustrating that the System wouldn't simply tell Erryn what it needed to do to lose the errant tag, and having to wait a year between each experiment was going to be annoying even in this timeless world.

Would Erryn need a new name if it did lose the tag? It was kind of the basis on which it had picked the name in the first place. Probably not, Erryn decided. It was likely to pick the designation back up again at some point, once it was done poking around the store.

In the process of digging out new floors, Erryn had needed to reinforce its core multiple times as the pressure from the ambient mana increased and threatened to overwhelm it. Now that it was done it reinforced a couple of steps further, as far as the available mana would allow.

Dungeon core upgraded. Maximum mana capacity increases to 10000. Mana regeneration increases to 0.3/second.

Erryn grinned internally as it resisted the urge to pour 10000 mana into a slime summoning. Best behaviour, remember! The increased mana density had likewise given upgraded versions of its dungeon materials, radiant dungeon flesh and radiant steel.

Digging and reinforcement complete, Erryn swept its attention across the landscape. Nothing interesting had come into range so far; a few more towns, but no more cities. The architecture was noticeably different in the west of Erryn's territory than the east, more brightly coloured and decorative structures. The east was more subdued, prioritising function over form. Possibly that had something to do with the proximity of Soutso. Erryn was drawing close to Soutso now, and it would not be long before it hit some hilltop that gave it its first view across the border.

In the meantime Erryn went back to enchanting, making another attempt at combining sharpness and durability.

New skill unlocked: [Advanced Rune Carving]. Runes may now be carved into items to provide advanced enchantments. Two enchantments may be combined into a single item. Inferior skill [Rune Carving] absorbed into [Advanced Rune Carving].

That was... unexpected. The last time Erryn had attempted to combine enchantments it could see that the possibility was there, but it wasn't obvious at all how to make it work. Erryn had expected to need to spend lots of time experimenting and practising before managing to succeed a double enchantment, but had actually managed it on the first try. It was so easy. Erryn could see exactly how to combine the two structures and where to situate anchors to prevent interference. Why had Erryn thought it was so difficult last time?

It was true that increasing the ambient mana around the core made its processing more efficient. Erryn knew how much difference to its intelligence a few extra floors had made in its younger days. But Erryn hadn't really felt any different reaching floor one hundred, so had assumed it had reached a processing limit of some sort. How wrong it was!

Excited at the possibilities, Erryn starting spinning monsters out of ambient mana. Previously it was limited to the few lowest levels of slime, but no longer! Monster biology was so simple. How had Erryn ever thought it was complicated? Dogs, wolves and leeches popped into existence, looking confused. The System was equally confused, popping up messages about monsters spawning outside of its control.

No! Best behaviour! Erryn realized it was behaving like an over excited child, and absorbed the monsters. It had created the monsters on appropriate floors, and the System hadn't tried to interfere, so it shouldn't be a problem. Besides, if it was going to mess up then the first day was far better than the last. But Erryn fought down the urge to experiment with monsters, and instead turned its new found prowess towards the flows of mana. If Soutso was in the state Erryn expected then Erryn would no longer be able to rely on a constant supply of new cores once it crossed the border, so upgrading [Mana Control] to allow it to operate at longer distances would likely prove very useful.

There were also the new varieties of enchantment to play with. Looking over the options, the first few were for adding elemental attacks to weapons. Swords of flame, ice or lightning, adding additional magical damage on top of the physical weapon. There was a space affinity enchantment for creating storage items. That enchantment certainly deserved the title 'advanced'; it did not simply increase the internal capacity of a container, but messed about with geometry in such a way that every item in the container was simultaneously at the very top. Erryn could imagine that no-one wanted to go digging around inside a magically expanded bag for a potion that had ended up at the very bottom: The average human arm wouldn't be long enough, for a start. But while that was required for a functional storage item, Erryn was more interested in the expansion of space on its own. Erryn already had [Inventory] for storage purposes, but at a hundred floors deep it was already pretty far down into the bedrock, and digging was getting both tougher and hotter. How much further could it go? But if it enclosed itself in a spatially expanded bubble, Erryn could dig out thousands of floors without worrying about hitting magma, or accidentally coming out on the other side of the world.

Conversely, if it could reverse the enchantment and shrink space, perhaps this could solve its problem of range on the surface? If it made shrunken pathways along the surface, it could effectively move the border of its assimilated territory far closer to its cores. An interesting idea for the future, for sure, but building enchanted mythril roads across half the continent would certainly not count as best behaviour.

Erryn spent some time exercising [Mana Control] instead, shifting around flows of mana with ever increasing fidelity and at extended ranges. Sensing that this wouldn't be sufficient and that it needed something fundamentally new to add in order to evolve the skill, Erryn focused on how its class resulted in the generation of light affinity and how this differed from enchantments. And then it replicated affinity production manually, spinning raw mana into pure fire affinity.

The quantity was wrong. Very wrong. In the first fraction of a second a metre deep patch of ground had vaporised around Erryn's test site, and the air had turned into a blinding incandescent plasma. In the next, a kilometre squared patch of landscape exploded. Clods of lava rained upon the surrounding area, and thick plumes of smoke rose up to join the ever present smog above. The slimes of the nearest subsidiary dungeon jiggled in surprise as the whole structure shook.

New skill unlocked: [Mana Mastery]. Your control over mana and your perception of it has reached the limit, and it will bend to your every whim. Inferior skill [Mana Control] absorbed into [Mana Mastery].

For the first time in the history of the world, hundreds upon hundreds of kilometres of landscape somehow contrived to look embarrassed. That was really not the sort of success Erryn had been looking for. At least it hadn't done it anywhere near anything important. Erryn was reminded of another lesson it had learnt in its youth, back when it had accidentally exploded its first monster; adding new floors may add extra processing capacity, but they do not add additional common sense. With each new bump in power it became more essential to think before acting, less Erryn accidentally explode something important.

Lesson taken to heart, Erryn looked around with its improved mana sense. It could see the corrupted mana churning in the sky. It could even see where it was flowing from; as expected it coming was from the east, the direction of Soutso. It was now able to perceive the barriers around settlements at a distance, albeit not from so far away that it was particularly useful for deciding where to place subsidiary cores. In any case, its increased range meant that it wouldn't need to plant any new subsidiary dungeons for a while yet.

The void in the mountain remained a mystery: Erryn could still see nothing there. But that in itself was telling; Erryn could see gentle natural mana flows everywhere, so a void where there was no mana at all was obviously unnatural. Erryn couldn't even tell whether it was some sort of perception block or mana flows were actually being suppressed for some reason.

Erryn hit the hilltop that gave it its first view into Soutso. The border itself was marked out in part by a wide river flowing to the south, and partially by a pair of walls with periodic guard towers. The two walls were built to face towards each other. Obviously one owned by each country, each to defend against the other. The cost of maintenance and personnel must have been immense. Even the river was defended by a row of guard towers. Some parts of the wall were protected by barriers, so there would likely be a good cache of new cores available soon. Other parts of the wall were devastated, breached during the war. Erryn spotted a ruined town across the border, but nothing else of interest was visible from this distance. Having taken in the view, Erryn resumed eating up territory and headed for the border.