What exactly is Nightblood? (WoR spoilers inside)

[Green Hoodie Mistborn]

If you went to the Cognitive Realm before Nightblood was awakened, there would have been a glass bead that said "I'm a sword!". It held the idea of a sword. 

 

Then half the same level as a Divine Breath worth of normal breaths (investiture) was pumped into him, 1000 breaths, tied to the "ideal/idea" of "Destroy Evil". I believe, especially based on the WoB that says Nightblood = Shardblade, that he is a "DestroyEvilSpren" given life "artificially" by humans messing around with the magics of their world, as opposed to the cognitive entities that arise passively because of natural beliefs & ideals. There may be an Ideal of "destroy evil" in the Spiritual Realm which could attract/form a spren, but that is a very specific thing and so I think it would be very hard to have a spren of that type, especially because most people can't even really agree on what is "evil", it would be hard to form a spren around an idea/ideal on which most people can't agree. 

 

That is why I think he is warped, because unlike normal spren who seem to have some innate knowledge of abstract concepts (Syl, Wyndle, Pattern even...) Nightblood doesn't really. He is more like a hack to the "spren system" that the Awakeners managed to do, and now that his creator is dead, no one can draw the breaths back out to "undo the code" on the hacked system. His coginitive aspect of "I'm a sword" was super charged with all those breaths, and a sword doesn't "know what evil is" as Vasher says in Warbreaker. 

 

Syl as an honor spren can cognitively and intuitively grasp "right and wrong", I'm guessing so can the other bonded spren who we've seen. It may not matter to them, but they know what it is anyway. 

 

Nightblood doesn't have that conceptualizing ability, because he's originally just a normal object cognitive entity (which are basically mindless, c.f. "I'm a stick!"), supercharged and expected to have an innate tie/concept about things for which he can't conceive. 

 

Realmatically, based on WoB, we know he is the same as a Shardblade which means he's the same as a spren. I think practically though, he is an artificial spren who wouldn't normally have arisen without the intervention and hacking of humans and the magic systems. 

 

-sorry for the rambling, but I think I finally get my point across.