Hi! So about an hour in so far and loving it. It really does bring me back to SNES rpgs and I can tell you've put a lot of time and effort into this and it shows.
A few minor bugs and some constructive criticism so far (will keep giving more as I get further into the game):
So I'm using a game controller to play, as I assume the majority of your players will want to. There are a few glitches/ weird things with the controller setup. For one, the "cancel" button (I've got a PS controller so it's the X button) is glitchy on the battle menu. For a while, it seemed there was no way to go back when you've chosen an option from the primary menu (attack, magic, etc) which meant you got stuck. I figured out that the "options" button works but only after a while. The first time I tried to press the "cancel" button to back out of a menu, I had pressed "crystal" and my players didn't have any, so I needed to back out for the game to progress. Instead, when I pressed the "cancel" button, the whole game crashed. I haven't been able to reproduce this glitch since then.
When I got to the shrine and Mara cast that spell, there was no way to do it on the controller. I assume many of your players are going to want to be able to play the game 100% with their controller and not have to use a keyboard. Also the constructions were a bit confusing. There was just an icon with a key you had to press.
Also, for the text, I would highly recommend getting an editor for the english translation. It doesn't bother me since I'm playing the demo version and I'm also a game dev and I like the game, but I know players can be harsh and there are just a lot of grammatical errors that make it obvious that the text was poorly translated. So far none of it hampers my understanding of what's going on, but I just wanted to give you a heads up that it shows. As someone who is multi-lingual and also a native speaker of english, I can tell you that most native speakers tend to be less patient than native speakers of other languages with these sorts of things. I'll also say, in terms of making the game immersive, you end up not having a feeling that each character has their own distinct voice. This is more an artistic-side comment, but for text-based RPGs like this, it's really good for each character (at least the main character) to have a distinct voice.
From a more story development side: I came here for queer content so I'm sensing from the beginning that there is some kind of romantic connection between Sai and Raydir. However, the intro involved a whole lot of info dumping that was a bit hard to process: it wasn't until after the intro that I was even sure which character I was playing, nor was I sure which side the knights were supposed to be on (at first I thought maybe they were from the underworld?), so the betrayal didn't really "hit" that hard. A little more storyline building up the connection between Sai and Raydir, to get the players more emotionally invested in their relationship, would make things hit harder.
Also-- I'm curious... (no need to answer this. I'm sharing this now just so you can have a sense of the thoughts of a player who's about on hour into the game.) From what I've gathered so far, it seems like a portal hasn't been opened up before. So how have humans and demons come into contact before? How would the knights be experts in fighting demons if this is the first time they've come into contact?
Anyway, I don't want this to sound like I'm dragging the game! I'm just sharing this as a fellow writer/ developer/ creator in the hopes that some of my feedback will be helpful. I'm super enjoying the game and cant wait to see what happens next.