While the newfound guest to the room may not be aware, the room has been plunged into darkness by her arrival. Well, the causation is indirect--the gusts of air accompanying the summoning process seem to be the direct cause. While the surrounding furniture remains mostly unaffected--as there is nothing that could have been toppled over--the only light that had been erected by the mage has broken loose from its holdings and shattered on the floor. But even that shatter was silent compared to her arrival. 
The summoner awaits. In the darkness, their eyes are hollow, as if boring a hole through the air. But they accept the silence as if it is an old friend. They let their outreached hand fall silently, slowly to their side. 
This individual has plaintive features that can be seen even through the darkness. Yet, there is something like an air of elegance about them. Perhaps the more accurate description would be to say that everything about them seems natural, almost predestined. There is nothing out of the ordinary when seeing them as a mage. There is nothing out of the ordinary when seeing them as a human. They are simply someone with the hint of a smile on their face, which belies an air of curiosity. Their hair, which seems darker in hue than that of their guest's, remains neatly arranged around their face and across the side of their neck.  
"So, may I assume that I did not confuse a summoning spell with a wind spell?"
But of course that is impossible. The quiet certainty in their voice spells that fact out. These words are intended to be a greeting, even as they remain unmoving, maintaining the boundary between them and the pale figure somewhere before them. 

They tilt their body slightly toward the direction of her voice. "Oh, is it my fault? Then I will take my leave if that is what you prefer."
It's a joke, of course, but since a ghost of a smile has been on their face for a while now, it would be difficult to tell from their expression. However, they do raise their hand and arm opposite to the side the Heroic Spirit is closer to. With a wave of that hand, a light flares to life somewhere from within the ceiling, revealing a sizeable and quaint room. Other than the shattered light from before--and what is presumably a container of sorts that was intended to weigh it down and hold it in place--the room sports a tidily made-up bed, a long desk, wardrobe cabinet, and a long abstract painting of some sort whose frame must be nailed to the wall. The floor, meanwhile, is carpeted, with a similar colour scheme to the painting.  
Plainly, it's a guest room. One where no guest has actually stayed before, to the extent that the window never needed to be opened to air it out prior to the summoning process. To be honest, the space is a bit large to be a guest room, and it's almost obvious that the painting is only here to fill up space that would otherwise seem barren. Almost. 
"I hope this is better?" they inquire, lowering their hand once more and turning around more to face her. "I would certainly hate to disappoint a guest at first impression."
It seems they have some sort of liking for theatrics.

After waiting patiently for her to finish her words and motions, they give a nod and state, "In the flesh."
Lowering their head slightly, hands to the sides and slightly out. Right foot stepping back slightly, stopping while the weight is supported on the underside of the toes. Two seconds. A conventional curtsy.
"My name is Ambryll," they say, after they straighten back to a normal standing position. "I have no last name. If you wish to call me by my name rather than a title, then please feel free to shorten it or conjure any nicknames, as long as it is to your liking. It is truly a pleasure to make your acquaintance."
Standing under the light, they look plainer than what one may expect. ​Their hair turns out to be some hue of brown, at least at first glance–but theoretically speaking, it is closer to being some shade of red or pink. It’s unclear if it’s rather wavy on its own to begin with or if it’s styled in a more distinctive way. Their eyes are a rather beautiful violet-blue, framed by long lashes, the latter fact visible when they closed their eyes and smiled for the curtsy a few moments ago. Their style of dress is somewhat traditional–likely similar to that of many mages–but it couldn’t be called old-fashioned. Perhaps they would sport a ringmaster costume well. It feels vaguely as if they are accustomed to dressing formally, even though their current attire is not necessarily all that formal. 

They nod along a little as if in understanding. Still, they're surprised that she's revealing her True Name so readily. It seems in line with her personality. Well then, so too is this obvious surprise of theirs in line with their own personality. Perhaps they see no need to conceal their reactions.
Ambryll isn’t not very creative with nicknames, so they're already feeling a little bad in advance that they can't really offer too many alternatives for their name. It would feel right to do so, but at least they offered her the opportunity to conjure any from her imagination. For now, they answer her question.
"Mariecorinne..." They say her name in one go, tilting their head slightly with a slightly curious look, probably because they’re racking their mind to see if they recognise the name. “Your name does have a somewhat familiar ring to it, but I don’t believe you and I are from the same region.” They shift a little and untilt their head. “Hm, shall I briefly speak in my native tongue so we can see if there are any linguistic similarities?”
Given she doesn’t object, they then proceed to speak a short sentence that, despite being short, has absolutely no modicum of comprehension for Assassin whatsoever. There aren’t even any cognates.

(Would it be okay if her name is a literary term/figure of speech from another language in the present? I thought it’d be cool, so that’s what this POV is building toward lol)

(:D)

They speak another sentence before slightly shaking their head. 
"I assume no familiarity?" they ask, translating the second sentence, which they were supposed to switch back with in the first place.
At least now it's apparent where their accent is from. 
"By the way," they say with that small smile of theirs, "what I said was just a traditional greeting. Something like...'Welcome to my abode, esteemed guest.' The second portion is, 'It is my honor to host you here.' Though...oh!"
They clap once, lightly. Their face blossoms with some sort of excited recognition.
"I recall why your name sounds familiar. Marie-Corinne, it...well, I should say your name. As a term it means something related to delayed retribution, does it not?" 
The narrator imagines this is sort of a weird thing to be asked, sorry.

"I suppose it does, though in the same vein, I cannot claim to be very familiar with you." They bow their head slightly, with another slightly prolonged blink to accompany the motion. "I apologise, but I do mean no offence."
They don't seem to have caught any possibility of the mood changing. They're likely more preoccupied thinking how almost literally luminescent the personality of the hero they summoned is. 

The way they're following, it still feels like a bad thing--isn't imbalance sort of a bad thing?--but it's true that the imbalance isn't that great, so they nod in the end. 
"Very well, I won't."
Just like that?
"However, to balance it out, feel free to ask me any questions you would like," they offer, but then quickly add: "Not at this moment specifically, of course. I'm open to anything you would like to do in the present time."

"At this hour?"
The moment the question comes out of their mouth, the moment they realise that of course she'd turn out to be the sort of person who would go out at this hour. Besides, aren't assassins practically affiliated with the night? But for Ambryll, who ordinarily caps it at a late evening walk, they only glance in the direction of the window with a mere fraction of whatever excitement she must be feeling.
It's a tiny bit hard to see what's outside because of the inside light being turned on again, but it looks like the moon has mostly turned out of sight. It's rather dark outside, though there looks to be the outlines of many trees in the distance. 
For Assassin, the window probably feels like it's begging to be opened, with its two shutters and mysterious view that it's concealing. 

"I assume it doesn't for you," they answer cautiously. 
The air hits like a slap in the face. It's almost shockingly cold. That's saying something, considering the interior of this room isn't very warm to begin with. Midnight wind. Seems it's pretty late. 
Ambryll stays still, probably paying attention to what she's doing. It doesn't feel like she wanted them to leave, so they're staying for now. If she wants a tour of the inside, or ends up actually wanting to go outside, then all they have to do is fetch a coat or two. 
With the window opened, the view is a little bit clearer. If Assassin pokes her head out the window, she can probably see that they're a little high up, maybe second or third floor. There's mostly grass directly underneath, and an abundance of trees in the distance along with what appears to be a hillside somewhere to the left, obscured by what appears to be a very nearby building. Or perhaps it's the same one they're already in? 

"I see." It's a generic response they're putting out, but they sound genuinely interested. And they are--they're wondering how it must be for someone like her, who seems so lively and outgoing, to live in the role of someone who must avoid other people to fulfill her role. Or perhaps that isn't the reason behind what she's saying, and they're making presumptions. 
"There aren't very many buildings aren't here, but the exterior should be stable enough for you to explore if you'd like." Another half-offer they're putting out. "But also of note," they add, "this is a rather remote location. There aren't usually many people here in the daytime either. Please, take of that as you will." 

(there wasn't a notif for this thread lol just like the old days)

"Ah, this building is three stories tall." Saying it aloud makes them wonder what the etymology of the word is, anyways. A story as in a tale, and as in a floor. It feels almost like a personal oversight, so much so that they smile a little again as they think about it. "I do believe it to be situated on a good vantage point. So..."
There's no way to tell if they're feigning the motion of thinking or if they're just an exceptionally quick thinker, for after a brief head tilt, they ask, "Would you like to access the balcony?"

"It's in the next room. This way."
Without further ado, they walk back toward the door. Apparently cleanup will have to come later.  
The hallway is a bit dim, but even so, it's apparent that it's much fancier than what hallways usually look like. It's wide, too, enough to fit a small procession of people. There's a light every once in a while, but it seems most of them are turned off. So, do be careful not to slip on the polished tiling. 
Ambryll was being completely precise when they said the room would be the next--all that they need to do is just walk a little ways and turn into the room there. The door is unlocked, of course, so they can just step on in. Still, they pause for a moment before entering, and look back at Assassin.
"These are my quarters," they say with a shy smile, as if giving an explanation, but then, without waiting for another moment, they just open the door.

...to be honest, the fact would have been far from obvious if they hadn't introduced the room as being their own. There's a nice-looking desk and chair, similar to the other room, with a few small cabinets under the table and a book open to its first page. There's a bed too, of course, but the bed sheets are neatly folded into a box shape, and the bed cover is almost perfectly flat as if no one ever sleeps on it. There's a wardrobe cabinet, which is actually smaller than the other one, but there isn't any painting on the wall. A mother-daughter floor lamp stands a little ways from the desk. Currently, only the top light is on. 
Other than trying not to dawdle, the magus doesn't seem to be in a hurry. They walk to the end of the room and pull the curtains there back, revealing a pair of doors plus two windows to either side rather than a window as might be expected. How extravagant.  

To be honest, the narrator doesn't expect Assassin to care all that much. 

“Yes, seeing as the secret passageway behind the bed is a work-in-progress," they reply with a faint smile as they twist the lock to one of the doors and, subsequently, the door handle itself. Keeping their grip on the handle, they move outward cautiously.
It's immediately apparent that the wind blast here is much stronger, hitting the face and pushing back any loose hair. Ambryll's free hand immediately moves to make their hairstyle an impromptu ponytail, likely to prevent it from hitting Assassin in case she's close to them. Not that their hair is that long. 
The balcony makes the height of their current vantage point more apparent, since the window from earlier had a comparatively narrow frame. From here, the night in its entirety is made more apparent, although in an effect similar to that created by negative space, the scenery seems almost caged by the structures supporting the balcony roof. Swaths of shrubbery and trees stretch out to the far distance, while directly underneath the balcony there exists some hints of a path scraped out by common footprints that wraps and coils around the building. 
No other buildings or hint of life are in sight. This looks to be a rather secluded location.