What happens to Nightblood now?

[_joe_]

In RoW, Nightblood drinks in investiture until it is satiated, or filled. Does Nightblood leak investiture, and will be able to absorb more in the future, or is it now 'full', and doesn't have the power to drain investiture like it used to? If it does leak investiture, how long until it is powerful again? The foreshadowing seems to indicate there is a lot more in store for Nightblood, but now that it is full, I wonder how it will operate.

[platnumkid]

Nightblood does "leak" investiture.  Leak probably isn't the correct term, it's more like consumes, the way a returned consumes 1 breath per week.  It will be hungry again before too long.

[LuckyJim]

From what I understand, the black smoke he leaks is the Investiture he's consumed that has become corrupted. So eventually Nightblood will corrupt and expel enough Investiture that he'll be hungry and ready to use again, though it might take a while.

Brandon Sanderson

Anyway, Nightblood is named for the smoke he leaks, and he originally had a different name when he was created. Vasher himself dubbed the sword Nightblood after he had used it to kill the woman he loved. The blackness that leaks out is actually corrupted and consumed Breaths, the ones that Nightblood leeches off anyone who draws him.

Warbreaker Annotations (April 25, 2011)

So basically, if you ever wanted to know how a sword would go to the bathroom... now you know.

[AquaRegia he/him]

No further factual information to add, just my feeling that no power in the Cosmere can prevent Sword-Nimi from waking up hungry soon enough.