I kind of get where you are going with this.
I like to listen instrumental music "visually", if that makes sense. I suspect that, as part of a larger project, which your introduction suggests, the context of this might be more clear. I also suspect that the imagery is quite clear in your own mind. Run with that. Paint it for us with the instruments.
The darkness is good (I love dark), but I'm not quite getting a well defined image of where you are trying to take us.
I realize you are early in the project, so don't take that as a dig, but as food for thought.
As for the mix(so far), it seems to be at a point I was at with Khyber Pass for a bit. Individual instruments(and voices) are overly hot, and don't have their own space. This is where I pull all the faders down.
Bring them up slowly and EQ, pan, compress judiciously. Pay close attention, and you will hear the instruments sort of "pop" into place. Ultimately, you can get the loudness, but have significantly more impact, because the various instruments are cleaner and not fighting each other for space.
You've got a good start here, and I really like what you are doing with that piano.
Work it.