Thank you for your comment
The lightning is in fact coming from the ground and striking into the clouds, I wasn't sure if I made it clear enough to be noticeable. If I knew what to write in the description I would have explained some of the less obvious stuff in the picture. Maybe making the lightning at the ground wider would make it more understandable to the viewer.
I do think the clouds are inconsistent in terms of art style. I would 100% try to redraw them to look better.
The idea was that each character would get their own palette. However the colors I used for the devil were hard to work with and didn't contrast very well. There weren't many dark red tones. I could have used the brown ones at the end of the palette but I'm not sure whetever that would have been enough to make the character not blend in with the background. A different comment pointed out that the mage is also blending into the ground. Swapping the dark and light colors could be enough, but i'm not sure.
One thing I would like to redo is the ground. Currently it might not look sandy enough.
This is the first time I joined something like this so I'm happy to receive both compliments and criticism. This is probably the longest I've spent drawing a single piece (about 7 hours) and I love how it turned out.