The question gets a laugh and a cross of his arms.

"I've already insisted he buy something of the sort for himself. He has his own that he simply never bothered to request the train import, so he really has little excuse. No, I intend to study my old coat to figure out how the enchantments work, then add one of my own to shrink it so that it will fit you better. In the meantime..." He reaches into his pocket and holds out a chain of dark purple beads, with edges that seem to blur and fade into shadow. "This is a form of magical armor that will help offset that weakness to darkness of yours.

"As for the others with Personas...is it possible they are simply from a different time? None of those I know on this train are from the exact same time as myself, and Demyx is from my future despite having been here longer than I."