Innately, how much can a KR hold Investiture in it's Nalthian form (Breaths), if they are breathing normally? Would it act like Stormlight? Additionally, could Stormlight be used to fuel Nightblood or be condensed into a burnable Allomantic metal or Feruchemical metalmind? Would a Hemalurgic spike constructed of a type of solidified, condensed, Stormlight metal be able to steal a certain type of element? Is it possible to construct a sword with a blade of pure Stormlight, like a lightsaber?