It's luck more than anything else that led him to this position.

He's the only mage left.

Who knew that settling a new world was such a pain? Sure, the company was 'well prepared'. Sure, the former militia had experience moving around in the colors- For a few hours or a day at a time, then going back to a nice safe guardhouse. Not sailing and walking across an empty land, covered sea to sky in iridescence, carrying everything you still own on your back or on the backs of animals that are increasingly hard to keep healthy.

Storms. Strange wild beasts, adapted to the colors. The iridescence, which gets into everything, growing over your skin, your clothes, your supplies, unless it's well sealed in glass or washed in water on a regular basis. So they absolutely must stick to the river. There is no other option.

Dragons. Just one nearly ruined them. They pass over the land, a roiling storm of semi-random magic that those below must withstand. Established dungeons have some defense- Monsters of their own to fight dragonborn abominations, potent core magic to context the rain of elementals, of caustic metal, of poisoned magic twisted into barely-functional shapes, of corrupting force that transforms crops into thorns and livestock into bombs.

This one merely pelted the general area with lightning and deadly-hot wind, constantly and unrelentingly, for more than a full day. But that's plenty terrifying enough. The wrath of a storm, a force of nature lashing anything and everything with its fury. The only reason any of them are still alive is a convenient cave in the white cliffs of this bay, where they could pile up wood and rocks and mostly seal the entrance from the heat and lightning. When the dragon finally passed, almost everyone had burns. A few were partially blind. The weakest among them, wearied by the journey and the iridescence and thirst and hunger, perished during the long days of sheltering in a dark hole, hoping the dragon would leave soon.

Their supplies: Mostly gone. Tents, bedrolls, clothes, soap, nails, tools, food, water, rope, crates, bags, sleds, and every single boat they had been using to go along the coast looking for a good spot... Smashed to flinders by the lightning.

The most important things to know about dungeon cores:

1. They hold back the iridescence. The corrosive, sharp, malignant magic that grows on everything except perfectly smooth materials like glass, or on water. Outside of a dungeon's aura, any human will suffer tens of thousands of microscopic razors and needles growing on every surface of their body. Their skin. Their mucous membranes are mostly safe, having enough moisture to wipe away the colors- Eyes, the inside of their mouth, and so on. But the colors eat into clothes and tools and skin. Without access to plenty of water to wash off with at least twice a day, you will begin bleeding from thousands of cuts. It's a death sentence.

2. Dungeon cores are bound to a human mage, and give that mage great power. Whatever their discipline of magic, any mage can form a dungeon core, in theory. The exact methods, naturally, vary depending on the disciplines of magic each mage has access to. And the ways in which a dungeon expresses its power vary depending on that mage's abilities to manipulate it, too. Not that the average person knows this. Why would dungeon binders give away all their secrets, and plant ideas about usurping the core for great power in peoples' heads? No, most people just know that dungeon binders are like miniature gods within their demesne.

3. Oh yes, and dungeon binders are almost always in charge, by long custom and practical reality. Would you try to avoid paying taxes to a person who can make the ceiling cave in on you on a whim? Who keeps you safe from the all-consuming colors and can build great palaces or create terrifying monsters or grow fields of crops to fruit in days? Dungeon binders are in charge. Dungeon binders have always been in charge. Why would it be any other way?

They look at each other, silently considering. Does anyone really know this guy? He always seemed kind of quiet. A bit of a loner, sticking to himself and fussing with his tools. Sure, he'd light fires and dry things out and move rocks with magic when asked, he'd hang around the campfire and tell stories, but never about himself.

It could be worse, the whispers go. That horotract girl, Klimas, was actively mean. Prideful and smug, demanding that other people carry her things since she was doing all the hard work of messing with spaces and angles to make their walks shorter. Not unreasonable, even, but a bad attitude, a bad sign for what she'd be like as a Binder. But it could be better. Everyone looked up to Hessia, and her deadspeaking kept sickness and injury at bay. And the Montagues... Well, they were in mourning. Their clan head, Donovan, was going to be the Binder. It was already set, pre-planned back home. A wise, cunning, and fair man, his reputation went- Perfect for a new demesne. 

So, yeah. Who is this guy? What's he going to demand of us?

Also, a bunch of people are dead and everyone else is in bad shape.

They mill around uncertainly.

The vastly expanded magical senses are giving him a fucking headache. But people need direction. They're like sheep when nobody steps up, and the only one who's a natural slot for a leader here... Is him. And maybe Hessia, but she's unconscious.

He could hide in the little offshoot-cave... Let everyone panic and run around like chokers with their heads cut off. That would be easier. But even aside from practical concerns of 'wanting someone to make food for him', he's not that heartless.

Who is... That guy. He remembers that guy, being a busybody about how much food was left and muttering sums on an abacus. "Mister Cooper! Do you still have your abacus?"

The man nods uncertainly.

"Okay! Everyone! The dungeon is established. I'm going to be working to get us stable. The dragon was really bad, and now is the moment to work together! Mr. Cooper! I need you to work with Mrs..." Shit shit shit, what's her name, the nurse, she has a name, "Mrs. Vale and whoever she chooses. Gather all the injured so we can take care of them properly! Take a tally of what you need to care for them, and what you have, and bring me the list. Because this is an emergency, I want everyone to work together. Offer Mrs. Vale anything she needs to care for your friends and neighbors! Our first priority is making sure everyone is healthy! Then we can figure out what to do next!"

The rest of the day is one massive headache. People start bugging him for miracles- But he doesn't understand the new magic yet. Not really. All he knows how to do is move wisps around, like before. Except with literally no range or power limit. Everywhere in the core's range, he can claim and feel, aside from little holes where people and animals are. The limit on his magic is not his power, but his attention. It's a breathtaking feeling. Just... Will the stone to flow, and it does. Multiple tons of rock, shifting at his command. He has to do it slowly enough not to send shards flying or accidentally crush anything, but that's all.

There are other things there, other levers he could pull to do magic, but he doesn't dare poke them. This is not the time for experiments.

Instead, he makes a set of basins. He makes a stone pipe going to the sea. He makes an evaporator and condenser, using brute-force magic to imbue horribly inefficient bindings to draw up distilled water. 

And now their cave has sinks and drains and running water. It took an hour. Not days or weeks... An hour. Dungeons are amazing.

...Toilets are the next thing on the agenda.

Every Dungeon Binder has Lords- People entrusted with their authority, to delegate the boring parts of ruling to. Mister Cooper feels like a bureaucrat. A micro-manager. The kind of person he would hate to have as a boss. So he's not going to inflict the man on his... Citizens.

(He shivers.)

No, someone else. Though he's not really sure who. He kept to himself on purpose, and certainly doesn't just want to choose someone he knows if they'll be bad at the job. He doesn't want to institute some kind of election either. That way lies... A lot of yelling and demands and fuss and maybe having to make a demonstration of why dungeon binders get to do whatever they want.

Which he'd really rather avoid. Better to be in charge because he gave them running water than because he can kill them.

A little kid comes up to him with a plate. On the plate are beef jerky and a baked potato, plus some mediocre local foraged fruit.

"Are you gonna make monsters now?" The kid asks. "My mom says dungeons have monsters."

"Hmm? You know, if I do, you'll be the first to know."

What is the deal with monsters anyway? Why are murder-gauntlets a thing? The first thought is 'defenses for his private rooms', so no fellow mage can kill him and take over the core for themselves. But that doesn't explain it. Covehold Demesne had four or five murder-hallways, which people actually had to sign up for opportunities to enter. They leave with meat and claws and leather and all the other things that animals make, and sell them to butchers and other craft industries.

What features of magic, he wonders, makes that make sense? Makes it the ideal shape of things?

Can monsters like that only be made hostile? No docile cow ready for slaughter, but an uncontrollable mass of malignant magic? Why not have the dungeon binder kill them himself, then? Is it not possible? Does the process of people murdering them generate some sort of resource for the dungeon binder?

He has no idea. And within a few weeks, he's going to have to figure it out. Dungeon runs are a lot of places' primary source of meat.

He gets back to work in order to feel productive. Excavating large sections of stone underground piling it up outsude for use later. (And telling peolle to stop blocking the way!) Making the cave smoother and larger. Adding ventilation shafts. He dispatches someone to map the area, and someone else to salvaging what can be salvaged.

And then suddenly there's a lot of screaming and yelling. Over, apparently, the remains of a ruined boat.