Jack let Cain meet and talk to you, he's fascinated by you being an actual spirit elemental thing. All the spirits in his world are either dead people police or people who get stuck and end up warping horribly and shit. HE'S CURIOUS.

Also I'd like to continue in the vein of Cain prodding and poking at Bakura to see what's up with him. :3c He's interested and wants to get closer!