Cayde nods. "He told me how materia's used to do magic- like...the knowledge of past, natural magic users, crystallized or somethin'." Which is still a weird thing to process. "And the more you use it, the stronger it gets until it makes something new." He gestures vaguely. "I'm super-paraphasing.

The admission of being a failed experiment is something of a surprise. "Failed how?" It's hard to read that metal face, but there's maybe the slightest shift of his metal brow. Yeah, he is not a fan of loss.

"Hey look. You don't have'ta explain if you'd rather not. Stories, especially past ones, ain't all impromptu dance missions and frilly dresses." He keeps going back to that but there really is no better contrast that he can think of.