It's nice to see some fresh stages with originality, especially coming from new creators.

Congrats on the ripping and creation process.

Now, some feedback for
Frozen Throne :- Why is the stage named "b" ?
- The stage is not symmetric. You need boundleft=-boundright, which you have, but you also need the startx for the camera to be set to 0, as well as p1startx and p2startx at +/-70.
- Leave leftbound at -1000.
- Simple preference, but 30 for screenleft and screenright seems a lot. Usual value is 15, and even Capcom doesn't go over 24 IIRC. Players can't go close enough to the border of the stage IMO.
- Use some fade.range to make the shadows fade out as a character jumps very high.
- Actually, removing the shadows to put some reflection instead may not be a bad idea, since they're on ice.
- bgvolume could be set higher than 0 (maximum is 255).
- The parallax used for the floor is far from being perfect, as the chars slide on the floor. Actually, I don't see much of interest using parallax for this floor. A normal floor with delta=2,2 would work perfectly IMO.
- Dunno if Mugen parses this well, but you have "type = paralax" (missing a "l") in your code at some place.
- I don't like much the black line (shadow ?) appearing and disappearing under the left ice block beside the rocker.
- If you look at the feet of all the BG characters, there is a cropped fog passing by, which doesn't look very pretty, as you can see the delimitation line, especially on the axe of the big left beast. Maybe try to apply some blur to the fog sprite.