That is a very neat tabletop standard! Looks awesome!
About the void wretches. I see, what you mean, but I am not sure, that black with gloss and green eyes is enough? The idea is very cool, but I think it might be a bit too dull in the end? Could you maybe make a few crackling green lights on the models here and there? Thinking of the manga image you linked to.
Or maybe some extreme edge highlights on the black here and there? Still glossed.