When you've been with the Scions for a while, you tend to pick up some knowledge or two. Especially things regarding souls and what not. And, uh.

Keep this between you and me, but what I described was actually what literally happened to some friends of mine.

[ He meant the Scions, and since she's the only one he's met from his home, regardless of Shards, that meant there's at least some implied trust he's giving her. ]