She kept crawling through his crystals drawing in more and more. Then she felt the barrier. The barrier she had been waiting to feel. Those were the crystals that he was already using, the crystals full with the spells she planned on breaking.
It was difficult for her to displace that spell. Pushing at it. Little by little she forced her way in.
Then it was over. Cockatrice breathed a long sigh and Demon of Forgotten Soot transformed back into a crystal.