Waiting for the ice to finish melting was a little annoying, but it was the only way for Mordecai to be sure that he didn't make any mistakes adapting their inhabitants to the environment. At least in the meantime, it made for an interesting environmental challenge; even with the airy water runes in place, the water was cold enough to be hazardous, plus the occasional flow of slush across the shallower portions of the path could make traversing it difficult.

So, instead, he turned his attention to the sewer. The diluted dark waters from the underground faerie lake had proven stable when he isolated it, and now the fae waters were carefully introduced into some of the isolated 'wilds' they had preserved when claiming the main sewer route. These wildlands were kept entirely separate from the main route and all other interference for now; they were needed to help them maintain Kazue's life-saving boon, thanks to some of the creatures there having crossed the spiritual threshold where the boon would 'notice' them.

There wasn't much immediate impact when the fae waters mingled with the mire and came into contact with the wild creatures, but after some time spent in observation, Mordecai could pick out a few trends and predict where they were going to develop, though not every creature acquired every trait.

The first was 'stillness'; those creatures affected by this trait were able to go into a very still, death-like state.

In this almost-stasis, they could wait indefinitely for a target to approach. Coming out of the stasis did slow down the launch of their ambush, but given how hard they were to detect beforehand they could wait until their prey was very close, making that delay matter less.

The second was just a simple resistance to both void energy and instant death spells.

Death-attuned spells came in two varieties. The spells that could 'simply' cause a healthy target to die were not common and were amongst the highest-ranked spells, though life's natural resilience rarely allowed such a spell to be completely successful unless there was a vast difference in power between the caster and the target.

Other, more common ones ensured the death of targets that were brought to the knife-edge of life and death if the spell was not resisted. Spells designed to take advantage of a weakened state were much harder to resist.

Targets of such spells completely died, down to the smallest bit, which in a small twist delayed the onset of decay by killing the multitude of minor creatures that were hosted by a larger creature's body.

The third was the ability to become slightly spectral.

They could not become truly intangible or ethereal, but they could shift slightly out of sync with the physical world. This made purely physical attacks and defenses less effective than they otherwise would be.

The future potential of such a power to bypass physical walls was concerning enough to cause Mordecai to double-check the dungeon's ability to contain such creatures. A wild ecosystem like this was not controlled the way inhabitants would be.

Mordecai manifested his avatar near a section of living crystal and cast a spell to make himself intangible before he attempted to walk through it, and then repeated the test with other variations such as becoming fully ethereal.

Living crystal alone proved sufficient to stop him from passing through with simple intangibility, while fully ethereal transformations required the living crystal to be infused with Sarcomaag's tendrils, and thus his spiritual presence, before it could prevent Mordecai's passage.

Naturally, taking a full step into the shadow or faerie realm potentially bypassed such barriers, depending on the physical configuration of that realm relative to the dungeon, but that was not much of a concern given the nature of such realms and a dungeon's spacial compression:

The shadow realm was already infamous for the treacherous ways in which it compressed and twisted distance and direction compared to the mortal world. Overlaying that with the spacial compression of a living dungeon made it even more perilous than usual for most to travel there. Naturally, dungeon inhabitants who traversed this region were not adversely affected by this combination, though they still had to cope with the effects of the shadow realm itself.

Faerie was normally a larger step away from the mortal realm and for any other dungeon, it would have the same issues as traversing the shadow realm. For the Azeria dungeon, well, that was no longer an issue as their faerie domain mimicked their dungeon territory's spacial coordinates, but that did not make it automatically safer for others to traverse. If nothing else, such intruders would be quickly noticed and inhabitants could be diverted to deal with them.

Mordecai made a mental note to ask Satsuki to verify spiritual projection and whether it could penetrate the living crystal. He wasn't particularly worried about it, that sort of non-physical planar travel was ill-suited to traveling in the physical world to begin with, but it was also not something he could check for himself, nor could he teach such a spell to Kazue, and it was not part of Moriko's skills.

The problem was that such spells actually projected the soul while keeping a tether attached to the body. A dungeon's soul did not leave its core, so an avatar attempting to cast a spell to project its soul automatically failed. In a way, an avatar was already a projection of the self, it couldn't create a second projection. Spells that created temporary duplication of the body were a different matter.

Once he was done with that, Mordecai turned his attention to ensuring that the dark waters would not leech into the containment cells.

A case of literary theft: this tale is not rightfully on Amazon; if you see it, report the violation.

Finding that some of the wild sewer denizens had enough of a mind and spiritual self to trip the dungeon's revivification safety had been quite a surprise and was a bit of a nuisance. The containment cells were much simpler than the prison cells that had been created for their invaders as Mordecai didn't have to worry about spiteful self-harm or the like.

The rules about safety and the one-year waiting time applied to these creatures as well, so Mordecai had constructed these cells to hold and protect individual oozes and slimes that had become large and complex enough to manifest a significant enough sense of self, along with plenty of room to move about.

Mordecai tried to provide a bit of stimulation by varying which sections of the sewers their 'feed' came from. These not-quite-prisoners were a little simple to experience much in the way of boredom, but they were hunter-scavengers with enough sense of self to trip Kazue's boon, so they had need of some stimulation.

It had become one of his best bits of leverage for slowly recruiting them. Weeks of peacefulness with plenty of food and no threats tended to be calming, which let Mordecai try again on his offer to help them become something more. It was still basic, emotional communication in trying to offer the bargain, but it was enough.

A few of them remained perpetually hostile, however, and the boon required keeping revived creatures safe.

He could foresee a loop that he didn't particularly like. Contain a revived slime for a year, release it into the wild sewers again, and at some later point have to do it again. As they became more intelligent, they would have more issues with containment, and it would slowly become more problematic to contain a free-willed creature. There was also the question of how long it was going to be between the release and a new revival. On the plus side, the organisms that tripped the boon tended to be a lot more dangerous than the ones who didn't, which meant that as long as he kept them spread out enough to not encounter each other, they should not encounter any other wild creatures that would be hazardous.

Unlike with a normal delver, Mordecai couldn't just release them someplace safe on the edge of their territory. Aside from the issue of them not being safe to others, they were not capable of complicated enough thought to understand the boon and be aware of the consequences if they died again inside of the dungeon's territory.

That was as much as Mordecai felt he should do with the living creatures of the dungeon for now, so he turned his attention to the complicated matter of the materials Satsuki had brought them.

What almost no one outside of dungeons knew, or needed to know, was the true nature of materials like mithral and adamantine. If one scrutinized the strictly physical composition of the bits that had mass, the materials were generally not that exotic.

What made them special was the non-physical components. The tiny nodules of magical and spiritual energy that took up space and connected the physical components in a complicated web that had a specific resonance. That was why mithral and adamantine took so much more effort to duplicate than simple metals.

There were exceptions, but they were the sort that proved the base rule. Crystallized elemental essence was not made up of normal matter, it was condensed elemental magic frozen into a physical form that gave it a sort of false mass. It was easier to make a steel alloy containing elemental crystal dust than it was to shape a weapon out of pure elemental crystal, and this was still very far from normal metal alloys.

All of this was in contrast to what made the materials Satsuki had brought so very, very special.

The precision of composition and structure was no less complicated than the magic-infused materials, and the metals involved were often rare and exotic; at least, as metals. Mordecai had never realized that part of the base composition for corundum gems and emeralds was a metal, yet here it was in the trinkets that had been brought over.

It was even lighter than mithral, but it compared poorly to steel in strength by volume. While it took a bit more force to deform, it failed completely very shortly after deforming. In pure form, it was also disturbingly flammable.

This 'aluminum', as Satsuki had called it, faired better than steel by weight, but that required increased volume so was a useless metric for most applications.

There were several more metals, such as 'tungsten' and 'titanium', that were also very interesting, but shined the most when alloyed. The precision with which they needed to be combined made them still more costly to create than simple steel and in some cases they were more complicated than mithral, but Mordecai foresaw a lot of opportunities to make use of them.

While he wasn't ready to work directly on creatures, Mordecai was trying to figure out ways to integrate these metals and compounds into shell, bone, and claw. It turned out almost every metal could combine with the base organic material of carbon, and most could combine with each other or calcium, which was the base of bone and shell. Getting them to do both at the same time was harder.

Some of his experiments had resulted in immediate and very rapid decay of the material, with corresponding production of heat and sometimes concussive waves.

Recreating those experiments in a safe, 'dead' atmosphere did not produce the same results. This was good to know as a data point, but not immediately useful.

Also, water not only didn't help, but for some experiments it accelerated the process. Non-magical fire that could burn underwater was a novelty that had distracted Mordecai's core for hours until Kazue mentally poked him.

He was able to show her several new crystals he'd discovered that made her quite pleased. Most of them weren't useful as proper gems, but they were at least pretty display pieces.

Moriko was happy to be his materials tester. Any alloys he found suitable he either made a weapon out of for her or made into armor to put on a training dummy.

Mordecai politely declined her offer for him to be said training dummy. He loved sparring with her, he had no intention of just standing there being hit, no matter how dramatically she pouted at him. When she was done with her game, she gave him a kiss and ran off to play with her new toys.

While they could add items made out of these metals to earlier zones, the three of them talked about it and decided to introduce the new metals slowly, starting with this ocean zone.

Of course, no matter how many experiments he performed and creations he made, Mordecai couldn't know for sure how they'd behave once the materials were fully real.

The mana set aside to make rewards became fully real material only when the items were claimed by delvers.

Similarly, the mana for their inhabitant's bodies became fully real immediately, but with the caveat that some of their abilities were powered byt the core, just as the bond between their souls and the core made it possible to actively retrieve their bodies and relocate them.

Internal avatars were more like his experiments: very detailed mana constructs running simulations of physical builds. It was the fully invested avatars like Kazue's that were completely real.

But there were only a few days to play with everything before the midwinter solstice. Mordecai carefully made sure to unmake his experiments the night before the three-day celebration for the twin goddesses began.