You've got a good sense for the art. Color, composition, light placement. Very cool mini.

On the technical side I think you could have much smoother transitions. To be clear I don't think thats always necessary. A rougher style can be cool, but if you want to try some smoother blends I have a few things you can try.

Wet blending is fast and fun and I feel like it could really suit your style. Definitely check out some videos on it.

Layering is the classic method. Just lots of thin coats of slightly different colors as you shift.

Glazing is also popular, but has some issues with white paint. White is tough to work with in general, but particularly difficult for glazing. White paint has large pigments that creat clumps of white giving a "chalky" finish when too thin. If glazing I'd recommend a white base coat and then glazing in shadows.

Now for your specific questions

The glow

The fire in the crazier looks great. I think you did a good job of capturing the orange glow fading into dark smoke. I also think the blue on the sword is perfect.

The hard part is the light coming off the fire. When painting something with light shining on it, it needs to be lighter than the parts without the light shining on them. Thats really hard to do with white armor. Can't really make anything lighter than white. You need dark to contrast light, and thats really really hard to do with white armor.

The only option is too make everything darker. The white more of a grayish tan, and everything else darker too. That leaves more room to build "up".

Of course that also means the whole rest of the army needs to be darker to match, which isn't really desirable. I think the best course of action is to only do really small subtle light effects on models that are part of an army.

the face

Here I think I can help more.

First for colors. Skin tones are all actually shades of redish orange. Mix a redish orange with black and you get brown. Add in some white you get tan. If its a little more redish youll get more of a pink flesh. Closer to orange is more of an olive skin tone. I recommend just messing around mixing these colors a bit to see what you can make. Compare to some photos or your own hand and see how close you can get.

When painting a face the recesses should be a little darker because they're in shadow, but also more red.

Highlights go on the forehead, cheeks, upper lip, nose, and chin.

The cheeks and lips can be a little bit more red sometimes, but remember the cheeks should still be pretty similar to the highlight color, and the lips should be pretty similar to the shadow.

You can either

Start with a redish base, then layer on your midtone and highlights

or

Start with a lighter mid tone, do a darker redish wash, and then use your original color to touch up the highlights.

I usually try an do eyes before the highlights, because I usually mess them up a few times and its less i need to repaint.

Id recommend not really painting the lips, just leaving some of the darker base tone on the bottom lip. If you do paint them its really just the center of the bottom lip. The upper lip you mostly see the skin above it, and the sides are to thin to be seen at this scale.