But he has a really good reason.
He destroys, and he moves.
"That actually sounds really plausible."
Snort. "Well. I am good and endorsedly proud of my wing accomplishment."
"It's a pretty good wing accomplishment!"
Flap flap. "How do I do the Sphere thing? Do I have to learn how to fly, you seemed to have it down fast but you also speak Gatetalk for magic reasons..."
"I dunno how long it takes people to learn to fly normally. You make a portal by, like... making one? It's not super hard but maybe I just think that because I grew up around this stuff and I already knew basically what it was all about the first time I tried it?"
"Hmm. Is this a good place or is the topology likely to change?"
"I've been leaving this particular mountain mostly alone so you'd have someplace to come back to that wasn't under a bunch more rock than it was when you left. I can keep doing that."
"Thank you." Cor frowns at empty space and attempts to make a gate.
Tias watches curiously.
It's pretty easy to figure out how to make a portal; once you're trying, it sorts itself out pretty quick.
There it goes.
Cor goes in.
Tias was not technically invited, but he follows anyway.
Cor doesn't object.
They are on the front porch of a pleasantly temperate stone house with a garden full of flowers and dwarf fruit trees.
Abruptly, in straight lines each of the four cardinal directions away from the house, the landscape changes: there a sandy beach with little castles and arrangements of seashells, there what looks like a riverbank, though there isn't enough of it to see a corresponding river; there a foot of snow, gently swooping over suggested underlying shapes and dotted with bird footprints; there a layer of picturesque red-gold leaf litter. The Sphere isn't big enough to show any more than those little slices.
"Aww!" he says, grinning. "That's really cute! If it does a whole pattern like this I bet it'll be a mess when you're a few thousand years old. But like a great mess."
"Is it likely to cut it out after a few more squares?" he wonders.
Shrug. "Who knows? Mine's got a whole coherent thing going on with the mountain and stuff, Dad's is literally just grass, I've heard there's somebody's that's just a big house that keeps growing more house without ever getting an outside..."
"Does it not even have windows?"
"I've never been there, but it didn't sound like it!"
"Sounds like a kinda depressing house! I like mine, it's cute."
"Is not having windows that depressing?"
"I guess I don't know how it's lit, but I'm used to houses having plenty of windows."
"—oh, right, light comes in windows when your sky's got a sun in it."
"Oh, yes, I suppose that's a hidden assumption."
"Yeah. In Aluvanna windows are more about how much you like looking at the stuff outside your house."
"Which I'm used to but could dispense with much more easily than light!"
"Come to think of it, my eyes should be killing me after all this time under an actual sun. It's probably the magical powers again."