You were sent into the past by someone named Nightbringer, cutting all ties to the present. Solomon went to accompany you, he is trying to find a way to help you come back to the present, while staying in the past. You both stay in Cocytus Hall. And Solomon would be lying if he says he doesn't enjoy having you all to himself. But — he doesn't enjoy seeing you so restless when you're overthinking about how you may not be able to get back to the present time.