I wanted to help you guys picture some of the stuff in the story, mainly the clothes because it's hard to describe some things in detail without getting really heavy-handed with the adjectives. I'm sure you don't want to read about a robe or a dress for a paragraph, and I don't particularly want to write that.

There are also few female characters, so at least this way you can imagine what the inhabitants of the palace might wear.

Like I mentiond, the setting is not based on one specific culture. It is somewhat Persian inspired in terms of architecture. I drew a lot of inspiration from Game of Thrones for the clothing, and some of the elements of their costumes are reminicient of Indian clothing, with influences from other geogrpahically close areas as well.

So, here are some pictures to help!

For the women, lots of flowly fabrics and silhouettes, more colour than shown here. Kind of a Grecian look to some of it.

For the men, here's a mix of some formal stuff and some casual tunics and things. 

They all wear tunics and pants like I desribed on Daehyun in Chapter 2 for more casual things. Yongguk would probably wear something like the second picture on the bottom row most often in formal situations. Himchan I imagine to be more into the look in the first picture in the bottom row. Daehyun favours something more like the photos below, which is more Southern in nature (within this AU). Obviously these are very Asian in origin, so they're not exactly what he might wear but just know that when I say "robes" in relation to what he wears it's more like this and not like Roman/Grecian robes. These are thinner and less ornate than actual Persian robes, but the overall cut is not too different, and that's how I imagine Daehyun to dress:

EDIT: Thank you to RSparda, because their imagining of Daehyun's clothing to be similar to Oberyn Martell's clothing from Game of Thrones lead me to this and this:

and that's exactly what I mean by robes when I refer to Daehyun's formal wear! You can see why I say they are closer to Asian style robes but not exactly the same, right?

So that's it for now! I might add a post about the setting too, rooms in the palace and stuff. But I think the clothes were probably the thing that was most hard to picture so hopefully this helps.