But you're sad and your spirits are all down. [So how could he sleep? When he knows there is someone who needs help?]

I got a bit sad on the mission too, because I'm s'posed to be mister Zetta's shinki but I couldn't go with him because I'm not strong enough to fight big monsters like demons. But I don't think the train would of brought anyone who wasn't helpful at all and I bet you helped people even if you got a bit grumpy!