Coppelion may not be a favorite among the animes showing this season. I myself stopped watching it around episode 4 or 5. Too much crocodile tears I guess.
But I did come across the latest episode in Animax featuring the first appearance of these girls - Shion and Kanon, the Ozu Sisters. I have a soft spot for mentally demented psycho girls. I especially love Shion (the one carrying the boulder) - because of her air headed nature and that twisted smile she always sports. Adorable. 
This is done in pencil with a bit of white poster color to make those electric sparks. The paper was yellowish. I brought it out more using Photoshop editing.