Soullessness

Ah, pretty much. No soul of course, thanks to Amara. It's kinda like losing your appendix. You never really noticed it when you had it. But now, when I come to a moral crossroad, I ask myself, 'What would Mr. Rogers do?' And as soon as I nail that, I'm usually good. – Donatello Redfield, 13.02 The Rising Son

Soullessness is a state of being when a human has their soul forcibly removed from their body while still living. When a soul is removed, the reaction of the human can vary; some may turn violent, being set-off by the most minute incidents, others may show a glib indifference to their surroundings. One universal symptom of soullessness, however, is that the person no longer requires sleep. Sam Winchester's soullessness manifested in his near-sociopathic drive to hunt, working off of pure instinct and believing any loss of human life was acceptable for the greater good. The prophet Donatello Redfield was able to work out a method to keep his moral compass after his soul was consumed by Amara, revealing to Sam and Dean that he would think "What would Mr. Rogers do?" when he came to a moral crossroads, and once he figured that out he would be good about his choices.

A soul can be returned to their human host, but only if the soul still remains on the earthly plane. If the soul is released from its confinement, the soul will immediately return to where it came from.

Episodes

Sam Winchester

Season 6
Upon reuniting with Dean the year after being pulled from Lucifer's Cage, Sam initially attempts to hide his new colder demeanor from his brother. Despite the act Sam puts on, moments slip past that begin to alert Dean that something is off with Sam, such as remembering seeing Sam smile the moment the vampire Boris turns him. After Veritas is unable to force the truth out of Sam, Dean confronts him about what he is. Sam admits that something is wrong with him, but that he has become a better hunter and nothing scares him. He tells Dean he thinks he needs help, but is met with a knockout punch by Dean.

After calling Castiel to examine Sam, Dean learns that he was resurrected without his soul, which remained in the Cage with Lucifer and Michael, and is impossible for Castiel to recover. While trying to figure out who resurrected Sam, their search brings them to the Alpha Vampire, who remarks that he can smell that Sam is missing his soul and takes an interest, believing without a soul Sam could become the perfect "animal." Sam eventually reveals to Dean he has been continuing to put on an act, telling him he doesn't really care about him, only insofar as he needs his help. He also admits to the innocent people he has killed in the line of duty, telling Dean he thinks he should go back to being his whole self.

Realizing that Crowley doesn't hold his soul, and that getting it back could kill him, Sam accepts that he will not get his soul back and says he doesn't want it back. Dean, however, goes behind his back to make a deal with Death to retrieve it from the Cage and put up a mental wall to protect him from remembering the trauma. Sam summons Balthazar in hopes of preventing his soul from being returned, Balthazar reveals that Sam will need to "scar his vessel", making it uninhabitable through the act of patricide. With John Winchester having been dead for years, Sam realizes he will have to kill Bobby Singer. As the two engage in cat and mouse, Sam is able to gain the upper hand and capture Bobby. But before he can deliver the killing blow, Dean intercepts Sam and knocks him unconscious. Tied down in Bobby's panic room, Sam sees Death enter. As he pleads for Death to stop, Death tells him he would be putting up a mental wall to protect him before he takes Sam's soul out of his bag and places it back inside a screaming Sam.

Milton, Illinois

9.17 Mother's Little Helper

Deputy Jenna Nickerson

11.02 Form and Void
While trying to comfort baby Amara's crying, and when looking into Amara's crib, Jenna's soul gets consumed. As Dean and Crowley argue outside the house, Jenna, in her soulless state confronts her grandmother in the kitchen and kills her with a butcher knife, telling her she "always wanted to try this" before brutally stabbing her. After hearing her grandmother's screams, Dean and Crowley enter the house to find Jenna in a bedroom smashing angel figurines her grandmother collected. She begins to attack Dean, and as he pleads for her to stop, Crowley telekinetically smashes her into the ceiling, killing her.

Len Fletcher / Sydney

11.05 Thin Lizzie

Goldie Schmidtlapp

11.06 Our Little World
Goldie comes face to face with a young Amara late one night in a park. When Goldie asks if Amara wants something, Amara tells her that she wants to be like her and proceeds to consume Goldie's soul. Goldie's soullessness causes her to attack and attempt to kill her mother the next morning; failing to do so, she is taken into custody by the police. Goldie is later used as bait by Sam and Dean in order to trap the demon Marco, who had been sent by Crowley to kill all the soulless people Amara had been making.

Donatello Redfield

11.22 We Happy Few
In order for Amara to find the location of Chuck, she pays a visit to Donatello Redfield's home in Lewis, Oklahoma. Donatello remains defiant during Amara's assault, refusing to reveal God's location. His defiance leads to Amara consuming Donatello's soul to get the information.

13.02 The Rising Son
With the birth of Jack Kline, Donatello is drawn to Sam and Dean's location in Wyoming. It's there that he reveals to the brothers that Amara took his soul. He explains that he's worked out a method to keep his moral compass, which involves the simple mantra of asking himself, "What would Mr. Rogers do?" He tells the brothers that when he comes to a moral crossroads, as long as he can "nail that" he is usually good.

13.13 Devil's Bargain
Sam and Dean call on Donatello to decipher the demon tablet, to learn if there is a spell to open a rift to Apocalypse World.

13.14 Good Intentions
The unforeseen results of Donatello deciphering the demon tablet are revealed after he attempts to kill Sam and send Dean and Castiel to their deaths. Castiel explains to the Winchesters that the human soul acts as a filter to the dark energies of the demon tablet; without his soul Donatello becomes corrupted by the tablet, believing that he saw "the power of God" when he deciphered the text and that Sam and Dean want to take it away from him. Due to his soulless nature and corruption, Castiel suggests the kindest thing to do would be to end Donatello's suffering, a plan which Sam and Dean vehemently oppose. Instead, Castiel locks himself in the dungeon with Donatello and forcefully extracts the information he gleaned from the demon tablet, leaving him brain-dead and on life support.

Lily Sunder

12.10 Lily Sunder Has Some Regrets
A quasi-soulless angel hunter, Lily Sunder has been utilizing enochian magic to acquire angel-like powers such as partial immunity to other angels' powers, access to angel radio, and keeping herself young and alive. Each time she uses one of these spells, a piece of her soul burns away, bringing her closer to soullessness. She has already begun to lose her ability to dream.