Does the length of time you weild Nightblood when fully drawn affect how many breaths you need to expend?

[Inspector Morgue]

This question popped into my mind after I read Warbreaker. It was the idea if you could perform Iaijutsu with it, the amount of breaths could be concerved.

[+robardin he/him]

Yes, the longer you wield Nightblood (unsheathed), the faster the Investiture drains.

At the end of Ch. 74 of Warbreaker, as Vasher throws NB away from him before it took everything from him:

Quote

The pain in his arm was incredible, and his Breath was draining away at an alarming rate. Once it was gone, Nightblood would kill him.
Everything was growing fuzzy. He slashed through a final wall, finding the room where he had been tortured.
It was empty.
He cried out, arm shaking. Destroy . . . evil . . . Nightblood said in his mind, all lightness gone from the tone, all familiarity. It boomed like a command. An awful, inhuman thing. The longer Vasher held the sword, the faster it drained his Breath.
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.
Vasher knelt, arm twitching. The black veins on his skin slowly evaporated. He was left with just barely enough Breath to reach the First Heightening. Another few seconds, and Nightblood would have sucked the rest away. 

 

Edited August 15, 2022 by robardin

[offer]

I believe it does depend on the time it is drawn (there is a good example of this in an apperance of NightBlood in another book,

Spoiler

at the battle of Thaylan field

).

It is possible that there is some minimum cost to drawing it so even if you are doing it very fast you still need some breaths.

[MasterGhandalf]

I would assume so, as Nightblood seems to take Breaths from his wielder over time while drawn, not all at once the instant he is drawn, based on what we see in the climax of Warbreaker (he drains Vasher progressively over the course of the fight where he's used). But I'd doubt that it's possible to draw and then sheath him again so quickly that he wouldn't take any Investiture at all. After all, Nightblood's always hungry.