While Zane punches, ash flows into JJ's open wounds from hitting the cauldron wall, attempting to piece together whatever internal damage was done, and form a weak wall over where Zane's hitting. While he's doing that, JJ gathers himself, and grabs Zane's head with his open hand. He then hits the barrel of his shotgun against Zane's forehead, holding it there. He then fires the slug at point blank while attempting to squirm free of the blows.