The jeweled jumper had existed for all of an hour and he had already managed to hurl himself from one stalactite to another to avoid the rock pond and safely make it to the second floor. I couldn't help but be impressed.

He'd stayed about the same size as before, less than half a foot in diameter, but where he'd once been bulbous and slow he was now incredibly thin, many-segmented legs tipped in jagged claws and mandibles tucked close to his head. Everything about him was streamlined for speed and agility.

And oh, his colouring—no longer was he the barest red I could muster when I'd created him, instead a deep, rich scarlet like the brightest of rubies. Even his venom stained his mandibles red, dripping over the algae with a hiss.

A proper threat. I couldn't wait to see him in action.

The horned serpent had already slunk her way through the rock pond, easily twelve feet long with sprawling, antler-esque growths over her head; they were like diamond, crystalline and impossibly sharp, less than a foot long but twisting and complex. Her colouration had darkened until she was nearly all black, only the pale white of her horns visible in the gloom. Gorgeous.

She felt my interest and raised her head, flicking out her tongue—I pressed soothing thoughts back through our limited connection and let myself drift away. I'd let her find her own way through the second floor. Others were soon to follow, and I wanted to give her all the competition she desired.

Speaking of.

In the sprawling tunnel I'd carved between my canals and the river, something other than a silverhead wriggled its way through; the web of mana I'd woven over the entrance as an alerting system sprung to life, informing me of something long and twisting making its way through.

An aquatic creature. I immediately threw half my points of awareness towards it.

It splashed into the first room of my second floor, to the near six feet of water that had been building up over the past day and a half. Pausing, it swung its body back and forth to examine the new habitat it'd found itself in, a maze of canals and algae I'd built up in the best approximation of kelp I'd managed to construct. It was thin and narrow, over six feet long and a dark stony green with a yellow underbelly. No scales, oddly enough, which was enough for me to place it in the same category as the moray eels I'd hunted in my hatchling days, but its sides were covered in strange pockets thrumming with mana. Maybe water-attuned, for swimming?

A silverhead, separated from the two schools that had grouped up in the third and seventh room, swam before it. The creature's black eyes snapped on its location.

Lightning crackled out of its sides and fried the silverhead to death before it had so much as a moment to react.

Oh. Oh.

Yeah, I'd be claiming that schema, thank you kindly.

I was half a heartbeat from reaching for my connection with Seros before I paused, glancing back at the eel; it finished snapping down the silverhead it had killed, exposing its oddly shaped mouth it no doubt used to hold tight to its prey as it zapped them full of lightning-attuned mana.

Maybe Seros' scales would defend against that, maybe they wouldn't. I had no doubts he couldn't find a way to defeat it, not with his past track record; but it was exactly because of that track record I was hesitating.

Seros had always been the one to fight those that entered my dungeon, earning the most mana from the kills even if others helped out, always testing himself and growing stronger from it. The one time I had let other creatures fight, it had only taken two battles before they were evolving.

A dungeon couldn't survive off of only one monster, even if they were as strong as Seros. I let our connection drop, leaving the seabound monitor splashing through the back half of the second floor as he practiced his hydrokinesis. He would be able to grow strong if I gave him proper competition within my halls instead of relying on those from outside.

Instead, I reached for my silverheads.

Of the small population I'd spawned in the rock pond, only a dozen had been brave enough to swim down the tunnel I'd made to venture onto the second floor. Over a hundred others swept in by the river schooled lazily through my halls, claiming the dens the water had filled to.

I had no control over them, much like Seros before his Naming, but I could still speak to them in the echo of the mana filling the floor, little nudges to guide them away from my dungeonborn until only twelve were left, swimming placidly underneath a rocky outcropping. Only my creatures would be given this opportunity.

And then I snaked my way into their little minds and pressed in the image of the eel.

Dungeonborn or not, they still had all the instincts of their species; they immediately scattered, hurtling deeper into the narrow tunnels I'd constructed for them. I sighed. Idiots.

It's not here, I soothed, corralling them back together. A glance back at my core confirmed I had four points left, and at roughly a dozen silverheads a point, I used three to give them a more proper school. They settled down with strength in numbers, relaxing enough to try and find some algae to nibble on. I pulled their attention back to me.

But there is one within these waters.

They stared blankly. Maybe this was too complex for them.

I pulled up a rough picture of the eel, waited for their frantic swimming to die back down, and then superimposed it with a mental image of a school of silverheads bludgeoning it to death. At least a few of them did pause, fins wavering.

Then I slapped together the most beautiful den I could imagine, placed a happy silverhead image inside, and stuffed the whole thing full of enough mana to make a creature weep.

That got the idea across. Finally.

The school—over thirty, less than fifty—hesitantly poked their heads out of the den they'd hidden themselves in, the algae-light from above bouncing off their heavily-scaled heads in a scintillating rainbow. For half a foot long, they were some of the most fearful fish I'd ever encountered.

But still, they slunk out of the tunnel's protection and headed back to the starting room of the floor.

The eel finished devouring the silverhead, shifting upward to poke its head curiously into a few of the dens it passed; already it seemed content to stake its claim in my dungeon, living in an environment that suited it more than the plain stone of mountain rivers. When my mangroves finished growing and their roots extended properly into the water, it would have no easier time hunting than settling itself to hide between the roots, zapping anything that passed and feasting as it pleased.If you spot this story on Amazon, know that it has been stolen. Report the violation.

Not if I had something to say.

The school of silverheads finally entered the first room, the water rumbling overhead as it continued to slowly fill up the canals. They hovered, waiting for another to make the first move; but my mana sang sweet promises of dens and power. It wouldn't be long.

Finally, one of the silverheads who'd made the plunge and abandoned the relative safety of the rock pond darted forward to slam its armoured skull as the eel turned.

Safety in numbers; the others swarmed to follow, tails kicking out clouds of bubbles as they threw themselves towards one of their greatest predators. The eel warbled, thrown back from the first hit but able to twist around– I could see the pockets on its sides glowing, its lightning mana recharged by its meal. The silverheads continued on.

Electricity– light exploded between the two but the eel wasn't ready for a school this size, its strongest blast already wasted on earlier prey. A few silverheads fried but others merely drifted to the river floor, stunned and twitching, others bullheadedly throwing themselves forward.

They slammed into its side with a crunch.

The eel had no scales to soften the blow—it went flying back, tail thrashing. One silverhead had nicked its sides with teeth and hazy blood bloomed between the silver mass of fish; some of their eyes flickered red, something awakened. They threw themselves back with renewed vigour.

It whipped around, lightning sparking at its sides– but it wasn't meant to use so many charges at once. A few more silverheads faded out, stunned or struck by its massive tail, but the rest exploded forth, slamming into its side again and again and again–

One more hit and the eel fell, thrashing, and went still.

The silverheads… not quite cheered, but definitely celebrated, swimmingly wildly overhead as its corpse drifted down to settle on the river floor. They had been victorious against what had plagued their previous lives– the old eel had grown fat and lazy until the pretense of its own power. My dungeon had no place for those that didn't work to improve themselves.

I pushed calming mana into those that had been only stunned instead of killed, pulling the knotted threads of lightning out of their own innate loops; I stored the pattern of the lightning, already my mind running wild. Earth-attuned from the toads, whatever psionic abilities the horned serpent had, and now lightning; I could finally start developing true, proper traps for those that wished to invade. I was positively giddy.

Nothing excited a dragon more than progress, and oh, I was finally beginning to make some.

I pushed apologies through to my silverheads but tugged the corpse away from their gnashing teeth, letting them focus on the mana they'd absorbed from the kill; the eel hadn't given any number to be too surprised at, maybe as much as an old luminous constrictor, but already its soul spoke endless promises for other creatures in the deep rivers. I dug through its memories and found glimpses of finned sharks overhead, sand-burrowing crabs, even salamanders that glowed an unworldly shade of pale blue–

For a later date. I dissolved its corpse, picking through each level of its being to find what schemas it could offer me now.

Electric Eel (Uncommon)

Using lightning-attuned mana, this silent predator lurks unseen in murky water or overgrown foliage to wait for its prey to swim closer. Its attacks are short-ranged but there is no escaping, and thus it feeds on whatever it pleases.