As the severe headache struck his head, Blake had totally lost his consciousness. Not knowing what was happening to him nor when he would be arriving at the previous realm where he had lived before he was moved to the demon realm, which was the earth or the human world.
Blake remembered clearly everything the system had told him, from what he would be doing back on earth, how he would get back, and the limitations that he got as he and Robus would be put in 'disguises' while they were on earth.
So when Blake finally regained his consciousness, Blake couldn't help but hold his head as the severe headache that struck him earlier still lingered before it slowly dissipated and disappeared completely.