I want to draw something like that black dragon, but the wing is the most difficult part. I draw some shape, copy-rotate it, then apply Pathfinder minus front. Is my approach okay? I don't want to lose the symmetry, which is why I didn't use the pen tool and manually draw it.
A solution would be to find the middle point of the circle, before you cut it to a moon shape, then mark it. After that place the first "black spot" to the place where you want to have the first negative space of the wing. Then select that "black spot", press "alt" + "r" on the center of the marked spot. A window will pop up and you can choose the angle that for the next "black spot". IMPORTANT, press "copy". when you are happy with the placement, then press "ctrl" + "d" to duplicate the action of the rotation. Try it as long out until you have the result that you like.
See the image to understand what I mean with marking the middle point of the circle.
If you have questions, please let me know.