How could the boy not know? Castiel frowned for a moment. He found it hard to believe that Ryuugamine would have been experimented on when he'd only been here a day, so how had he missed the news about the illness?

But Castiel's nausea had been growing steadily since the conversation started, and it was starting to reach a point where he felt like something bad was going to happen, though he didn't know exactly what. He didn't know how to read this body or the signs it gave him.

"It means... There are a group of us that fell ill," he said, hoping that he could distract himself from how awful he felt with conversation. "But it's no ordinary illness. Those who let it go untreated will eventually turn into a monster of some kind." He sucked in a breath, hoping that it would help with the nausea, but it didn't seem to do much good.