The smith creates the GLASS CANON, whose split COUNTERPOINTS can pass light back and forth between them, magnifying it until it unleashes a devastating final attack. However, if you let it charge too long, they will SHATTER and release all of the stored light energy, KILLING YOU INSTANTLY. You say that's horrific, why would the smith make this? The smith replies that Dreamers can't permanently die so they thought it might be a good tradeoff. Also, its massive drawbacks mean you can get more attack power for less grist.
You say............... thanks.