Taln’s blade theory (Wind and Truth prologue spoilers).

[Ashbringer he/him]

Update to this: there's apparently now a Spoiler-Heavy update on the contents of the Stonewalkers campaign up on the kickstarter. I'm probably not going to look at it myself, because I'm more interested in maybe actually playing it - but that might have the answers that we seek.

[Green Hoodie Mistborn he/him]

I read it, it's not THAT spoilery, but specifically it doesn't speak to what happens to Taln's Blade