Japanese casting spoilers?

[Iscah]

I'm still hoping that they bring Carvallain into the AST questline during ShB; could be a wellspring of comedy and possibly some heartwarming moments.

That too, definitely! Would be a great place to resolve his storyline. (And possibly bring Rhoswen in as well for even more wellspring-of-comedy...)

Or could have it come up in AST separately to the Carvallain/Rhoswen running plot, I suppose.

I suppose it's possible, then, that Aoi Yuuki will just be there to talk about Dad of Light, but that still leaves the younger Uchida as a wildcard, and sure enough he's the second guest, right after Keita Amemiya talks GARO gear and Ivalice.

I'm not familiar with him, but does he sound like he could be the "mysterious voice"?