Ahh, you can try to use the light table then, for the shading. Not seeing the animation right now is tricky, but the bigger the flames, the brighter the light, and the further away they are, the dimmer the light. You can also rely on anatomy for shading, which I saw you did do that. You can make the shading fade and become darker and maybe blend more with the darkness, which would take more time but maybe also look more pro? I'm just throwing guesses and suggestions xD
Well it's not that I don't know where the light should go xD The issue is that when I animate it the shading is super wobbly. I just gotta figure out a better technique that's more consistent.
Ahh, I see xD Maybe you can be fast with your eraser swipes? Or try a different brush? Some of the brushes have some weird jazzy stuff to them you don't know about, like Photoshop brushes.