Can Nightblood Starve?

[Faceless Mist-Wraith he/him]

In Warbreaker, when Vasher was explaining awakening,  he seemed to equate Type I (Returned) and Type IV entities (Awakened metal). Does this mean that Nightblood also has a need to be fed within certain time intervals? Obviously if he does it's probably a very long time, since Vasher likely isn't unsheathing Nightblood every other week. But if a person never unsheathed Nightblood, would he eventually devour the 1000 "core" breaths used to make him?

Or in an extreme case, if a person unsheathed Nightblood and then threw him into a large patch of empty space, would Nightblood eventually starve?

[Calderis he/him]

I don't believe so. A sword has no biological functions that need to be supported... 

Spren seem to "feed" somehow passively from highstorms though, so who knows. 

[+Ark1002]

I do not believe so, because Nightblood has been in his sheath for long periods of time, Vasher almost never seems to use him. Without aluminum, I doubt it would change, I think the reason it is helpful is Nightblood just does it, but he doesn't need it. So if you threw him into a empty space, he would not take investiture, but he wouldn't starve.

[Solarserpent]

Nightblood contains more Investiture than the 1000 breath requirement for Awaken metal. It is an oddity that has not been explained.

I feel that if the splinters of Endowment, the Returned, require additional investiture to live then perhaps Nightblood does as well. The difference is that Nightblood can rip it from anything.

It could be that sentient things might require energy to remain awakened where as simple automaton do not. Preservation was required to instill more energy into humans to allow for sentient life which weakened him against Ruin so it could be similar. 

Being made of metal itself may also make a difference in power leakage also. Sounds like a good Word of Brandon question.

[Calderis he/him]

According to Vasher at least, Nightblood only requires Investiture when drawn. 

Quote

“They’re of the Fifth Heightening,” Vasher said, interrupting her. “But they don’t get there by the number of Breaths, but by the quality. Returned have a single, powerful Breath. One that takes them all the way to the Fifth Heightening. It’s a divine Breath, you might say. But their body feeds on Breath, like . . .”

“The sword.”

Vasher nodded. “Nightblood only needs it when he’s drawn. Returned feed off their Breath once a week. So if you don’t give them one, they essentially eat themselves—devouring their one, single Breath. Killing them. However, if you give them extra Breath, on top of their single divine one, they’ll feed off those each week.”

 

[Faceless Mist-Wraith he/him]

6 hours ago, Calderis said:

According to Vasher at least, Nightblood only requires Investiture when drawn. 

That's part of what started the question. What happens when Nightblood requires Investiture/is drawn, but isn't given Investiture for an extended period of time? Would he just become weaker or would his sentience eventually disappear?

[Steel Inquisitive he/him]

So if Nightblood were separated from his sheath, and left in space, he would eat himself?I

And if the Returned wore aluminum clothing would they not need more breaths?

[+Extesian he/him]

The question has been asked before but not really answered. 

Quote

Phantine

What does Nightblood do if he gets fully drawn and runs out of breath and people to eat?

Does he start vaporizing the ground and start boring a hole to the center of the planet?

Brandon Sanderson

No, he won't. (Good question though.) I'm not sure I want to get into the mechanics of why not, yet. It WAS one of the first things we talked about with Nightblood, though.

Phantine

Not to go into mechanics, then, does Nightblood just 'go to sleep' when his job's done?

That would explain how Vasher is confident he'll be able to get Nightblood back, even if the person he tosses Nightblood to ends up fully drawing the blade.

Brandon Sanderson

He doesn't sleep, but if he draws in enough, he'll start to sound drunk or drowsy (depending on your interpretation.)

source

I think he draws investiture when he's drawn because the command is activated but once he runs out of investiture to draw from a wielder he can't get more invested simply by touching things and the command wears off and he just becomes normal Nightblood again, albeit unsheathed. 

[Calderis he/him]

Honestly I don't think it does. In Warbreaker, when Vasher has Nightblood drawn, he throws Nightblood aside unsheated. Nightblood lands, puffs some stuff to smoke and then just stops. 

If it were able to feed on its own investiture like it does to others, or like returned, then that should have killed it. The effect caused when it's fed, the massive destruction ends, and then it just lays there. 

Quote

Gasping, he threw the sword aside and fell to his knees. It skidded, tearing a rip in the floor that puffed away into smoke, but hit a wall with a pling and fell still. Smoke rose from the blade.

 

[Yata he/him]

Nightblood is described by Brandon as "leaking" so it's not a matter of consuming investiture to remain alive as a Nightblood's need but it's a matter of don't leave NB to leak until he died.

The Aluminium coverage is there to stop the leaking mainly