Just played through the demo.
It's solid and reasonably polished. Something RPG Maker folks need to aim for.
The characters are pretty fun. I assume you're a fan of fantasy and RPGs outside of JRPGs since you gave all the men facial hair. It works. Somehow makes the PCs feel less generic, even if you're leaning into a few tropes (tropes are impossible to avoid, really, so it's not a negative; as opposed to cliches, like the hero Harold waking up in his bed).
I suppose, now that I think about it, what may fall into a "cliche" for me is the whole Light and Crystal thing at the start of the game. Seeing as the out-of-the-box RPG Maker is geared towards making JRPGs, it's hard not to see the similarities to Final Fantasy when you're going to use light and crystals. Of course, that might have been an intentional allusion on your part since that Light-wielding guy and the crystal was only in the prologue. If it never comes up again in the tale of our six heroes, then I think that would be a nice nod toward Final Fantasy.
Coincidentally, my RPG Maker project also has a number of characters thrown together early on (after being given a choice of who to start with) so it's interesting to see how you're handling it (lots of unavoidable overlap in our approaches). I like that you give the chosen character the ability to make in-game choices (in my game, I allow the player to control dialogue choices for all of the PCs, not only the one they start with). Your approach is more immersive in terms of putting the player in perspective of their chosen hero. I like it, and I assume you're going to keep having that happen throughout the game.
The combat and gameplay is enjoyable. You employ a lot of plugins I've noticed people clamoring for but I haven't played enough demos/games to see them being utilized well. The way you use them makes the combat satisfying.
Your choice of hair for Gregor is interesting:
Spoiler
For a minute, I thought the poison also changed Gregor into a woman, but I'm guessing those are supposed to be manly viking braids (or something similar). Also, I suppose, those braids aren't necessarily feminine in all cultures.
Anyway...
A lot of people respond to demos, complimenting people on their "effort" as a way acknowledging people's attempts at making something good (and sometimes it's actually good, sometimes, it obviously requires more work). Your effort is not merely an attempt. The results you're getting with this demo are already good.
Good luck, and I hope your work inspires others to polish their games as you have.
Oh....
Spoiler
Based on your avatar/profile image, I decided to trust that orc. Hahaha.