"Yeah, that." Right, they probably ought to explain. At this point, it seems kind of silly to keep it a secret, particularly since they do trust Buttercup more than a lot of the train. "I'm technically dead, Buttercup. The reason I'm still walking around anyway is this lantern. My life force, my energy, my soul-- whatever you want to call it. It's in there. Damage to the lantern damages me. One of the demons managed to get crush it. That's why I died."