What the Sage has to say is pretty much what Jack expected, minus the part about the Black Crystal. Okay, neat, they don't have to go into the Rift to go after their Shadows, they can draw them out here.

But Jack looks at Aang curiously. "Have you tried that trick, going on the crystalized lands, since you," he waves a hand in the air, "became like the rest of us?" And since half their group mysteriously died?