At the rate Shindou tatoo is growing I wonder if he'll be the one that turns into a full demon like Kureha's brother. The end of the opening seems to hint that there will be a fight between him and Rokujou with her looking sad that she has to kill him. And what I met earlier was how did Rokujou and her brother know where their tat's were if they had just woke up from coma's.