Brandon Sanderson: Nazh was born, as a character and as a concept, out of Isaac annotating maps, and wanting to have somebody... 'Cause Isaac was our original cartographer, been doing the maps ever since Mistborn, of basically all of the Stormlight books, until he started bringing some people in to do some of them.
Not just Stormlight, but all of the Cosmere books.
So if there's a map, or (particularly in the Stormlight books) ephemera, Isaac has had his hands in those, and he likes to add little easter eggs, and he came up with this persona of this character who was doing this. And we knew we wanted these to be in-world artifacts, but we also knew that we needed somebody who was kind of recovering these for some thing, and I'm like, "Well, this works very well with Khriss, probably compiling these and finding artifacts from planets and bringing them back to Silverlight."
And so, that's kind of where Nazh was born. I borrowed him once before for Secret History; he makes a small appearance in Secret History. Larger appearance here. Isaac and I have talked through his history and his future, and as early as years and years ago (probably seven, eight years ago), I'm like, "What about this?"
And that's when Nazh joined Starling's crew in his current incarnation.
Isaac Stewart: I think it was with Alloy of Law where we realized we need somebody annotating some of these, now and then. One of the reasons was, when you're doing a map of a city the size of Elendel, we couldn't really put these tiny street names, and things like that.
So we're like, "Well, we need somebody annotating this." And many things crashing together, but that was one of them.