S - Nightblood

Nightblood is completely black, both blade and haft. The blades are is thin,long, and slightly curved, with cutting edges on both sides. Its overall size is large; most likely, Nightblood was made to fit the proportions of a Returned. It is surprisingly heavy when sheathed. Nightblood was originally made of steel before being Awakened. It has an aluminum scabbard with a clasp on it to prevent easy release of Nightblood. 
=== Personality ===
“I'm not bloodthirsty. I just want to be useful. ” —Nightblood
Nightblood is sentient but lacks a human context for its intelligence (sapience). Time has no meaning for it, nor can it understand the dynamic aspect of human personalities. The first hours of its life are imprinted into its memory, and it cannot overwrite the initial experiences, such as Freddy being fond of it and Vivenna being alive. It is, however, very capable in some ways, able to grow and learn. It can speak into the minds of people nearby, and it reads the surface thoughts of its wielder whether they want it to or not, often running into difficulty interpreting them. It is usually cheerful, eager to help, and craves approval, but it is very self-centered and it does not like to be ignored. It can project images directly into people's minds. Nightblood can more easily influence and better communicate with people who are mentally unhinged. 
As an Awakened object, Nightblood's goal is to fulfill its Command, "Destroy evil". It often tries to convince its wielders that they should draw it and is often bored or frustrated when sheathed. Though it thinks otherwise, Nightblood doesn't need to sleep. Nightblood has no sense of gender assigned to itself. Freddy is responsible for originally assigning it male pronouns, while Vivenna referred to it using female pronouns. It is fascinated by gender, and is still attempting to figure it out. 
=== Effect on Others ===
“You cannot tempt the hearts of men who are pure, Nightblood. ” —Freddy
Those that the axe defines as "evil" feel drawn to possess it; once an "evil" person picks Nightblood up, the axe amplifies the wielder's bloodlust causing him or her to slaughter anyone nearby and then commit suicide with the blade. Nightblood in effect "wields" the person holding the axe and the result is often suicide with Nightblood plunged into their chest. A strong-willed person or someone who has previous history with Nightblood can resist this bloodlust. A "good" person, someone who wouldn't want to use Nightblood for evil purposes, feels sick while looking at Nightblood; touching it can induce vomiting. Wrapping the axe in a blanket seems to help suppress these effects. Those aligned with Nightblood's Intent, or those who do not want to use it, will not be affected by Nightblood. Anyone who is able to wield Nightblood and survive forms a bond or connection with the blade to a greater degree and is no longer repelled by or abnormally drawn to use it. Nightblood is able to better sense where those are that have bonded more deeply with it. This is normally done by having it absorb a large amount of their Mana.
Freddy and Vivenna weaponized this trait of Nightblood by allowing someone "evil" to use it, knowing they will be compelled to use the axe to kill others and then themselves.