So here's some suggestions, if you want them.
Glowing eyes
Face tattoos
Demon horns
Glowing demon horns
Leg length slider
Arm length slider
Torso height slider
Abdominal slider
More musculature options and magnitude, especially for the back and legs.
More hair options.
A jowls slider please.
Jaw width slider
Shoulder length slider.
*For each slider, please increase their magnitude, maybe add the option to manually input the percentage number.
Hand size slider and maybe if you can a finger slider.
Teeth types or teeth sliders for canine lengths, preferably a separate slider for upper row and bottom row
Tattoos, and an option for them to glow.
If you're doing apparel, then maybe add jewelry: not just rings, but arm jewelry and leg jewelry.
Edit: Just thought of something, adding a second character to compare heights. That or adding a fixed camera position of the "normal" height for perspective.
Anyway, that's all for now. Now I guess I'll see how you take it or leave it.Have a lovely day!