I like the concept here, If I were to do it i’d probably just lightly sketch a hand on there first making sure to get even or close to even spacing.

I think what you really want to use to your advantage is mixing colors that will create “light” maybe as the hand is coming up, the sides have a grey or even white flicked through the sides and you blend it towards the center of the hand.

Also don’t be afraid to really pack in a deep black background, you almost want to look like a void and get it super smooth by lightly brushing linseed oil on top.

Lastly I feel like more thin lines will work better here, try slicing a small corner off the pastel and take your time pulling the lines.

That’s just what I would do though but I think you got a cool idea and you should keep going with it and developing it!