Satella (サテラ) is the Witch of Envy responsible for the Great Calamity 400 years ago who is currently sealed in the Evil Sealing Stone Shrine, located somewhere underneath the Augria Sand Dunes, close to where the Pleiades Watchtower is currently standing. In reality, the Witch of Envy (嫉妬の魔女) is a separate personality that formed when she took in incompatible Witch Factor of Envy. Satella formally debuted in Arc 4 as a supporting character, whilst the Witch serves as an overarching antagonist throughout the series, appearing in pretty much every Arc so far, in one way or another.
She possesses a yet-unexplained connection to both Subaru and Emilia, and was also the one who gave Subaru Return by Death. Throughout the series, the Witch silences Subaru whenever he attempts to talk about his ability. Satella herself did not debut until Arc 4, where she and the other Witches helped Subaru accept himself and change his views on Return by Death.
Satella, according to legend, is a half-human/half-elf demi-human woman with silver hair and eyes that are amethyst with a bluish tint to them. As a half-elf, Satella's ears are noticeably pointed. When she manifested before Petelgeuse in a realm devoid of light, the details of her face and the shape of her body were both obscured by pitch-black veils made out of mist. The mist that engulfed her form was so impossibly dark that it blotted out the darkness of the realm. In this state, Satella's eyes can be seen glowing brightly in contrast to the rest of her form.
When she attacked the Sanctuary in Emilia's body, Satella's form was once again obscured. Although the contours of her body were difficult to ascertain, the shadows surrounding her made her seem as though she wore a dress of darkness and had long raven-black hair. Her voice was muffled to the point that it was difficult to distinguish whether it belonged to a man or a woman.
In the anime adaptation, Satella's clothing deviated significantly from the description provided in the light novel. In the anime, she wore dark-purple thigh-high socks with golden frills on the top, a dark-purple one-piece mini-dress with golden flower decorations, and a long dark veil that covered a part of her face.
When Subaru encountered her at Echidna's tea party, she wore a black dress made of shadows that seemed to wave in accordance with her heartbeat. Initially, he was unable to see her face because of a black shadow covering her above her neck, which was created out of his reluctance to accept her, however he later accepts her and becomes able to see her face, mentioning afterward that she looked exactly the same as Emilia.
Contrary to popular belief, Satella and the Witch of Envy are separate personalities, formed when she took in incompatible Witch Factors. The two personalities tend to fight each other. Both personalities love Subaru, though the Witch of Envy personality is much more aggressive about it, while Satella is much more reasonable and cares deeply about his well-being.
According to Beatrice, Witch of Envy was starved for love before her imprisonment. For unknown reasons, the Witch was obsessively in love with Natsuki Subaru, who, to his knowledge, had never met her before in his life. In the shadow world she called home, Satella would simply sit idly and monotonously repeat the words "I love you" over and over again, seemingly swamped by her own obsessive feelings of love towards Subaru. She was incredibly possessive over Subaru, as she wouldn't allow him to tell anyone else the secret of Return by Death. She seemed to have no remorse nor did she pay attention to anyone other than Subaru, as she didn't hesitate to execute Emilia when Subaru told her about Return by Death.
If the secret of Return by Death was revealed to another person, Satella would find a method of bypassing her imprisonment and slaughter all of Subaru's allies in that timeline, presumably as a form of strong reprimand fuelled by her possessiveness. Although she usually paid no heed to the words of anyone including Subaru's, she once took noticeable offence after Subaru told her he preferred the other Witches of Sin over her.
400 years earlier, Satella absorbed the Witch Factors of Envy, which she had no compatibility with, resulting in the creation of her Witch of Envy personality. However, this alternate personality was not the reason for her subsequently going out of control and killing countless innocent people and nearly destroying the world. Despite the efforts of many, including the Dragon, the First Sword Saint, and the Sage, Satella was unable to be killed and was instead sealed in a shrine that was watched over by Shaula, until the end of Arc 6. Currently, the Pleiades Watchtower and Evil Sealing Stone Shrine are being watched over by the Divine Dragon Volcanica itself.
Despite being physically imprisoned near the Great Waterfall, Satella somehow maintained a link to Subaru's body and was constantly aware of his actions, and even managed to manifest in the shape of a shadowy figure multiple times throughout the first four Arcs and in the 6th Arc.
Authority of Envy (嫉妬の権能 Shitto no Ken'nō): Satella is able to use the Authority of Envy.
- Although the abilities of the Authority of Envy have yet to be revealed, in the Web Novel, Minerva mentioned during the Witches' Tea Party that Satella might direct her jealousy (妬み Netami) toward her if she stepped in between her and Subaru, suggesting that it's something that affects people remotely. This ability has been removed from the Light Novel, hence should not be considered as canon.
Immortality: One of Satella's most troublesome and dangerous abilities is her seemingly-flawless immortality. Although she could be injured and defeated, Satella's body couldn't be destroyed by any external force. Even the Flugel the Sage, who was said to be all-knowing, could not conceive a method to bring about Satella's death. Her immortality couldn't be bypassed by even Reid Astrea, the first Sword Saint, Volcanica, the Divine Dragon and Flugel, the aforementioned Sage, eventually resulting in her being sealed away, despite it being stated that Reid was stronger than her. It is unknown whether her immortality is part of her Authority of Envy or a completely different ability. By the time of Subaru's summoning, Satella has been alive for over four-hundred years while still sealed.
Shadow Control: Satella is able to generate and control shadows on a gargantuan scale, though it's unknown whether this is a part of her Authority of Envy or a completely different ability. They erode or destroy all life and matter around her as well as taking abstract things like thoughts and sometimes even memories and mixing them together. It's also shown that she's capable of manipulating someone's feelings and emotions, amplifying or fabricating them to her own liking.
- Satella is able to create shadow tendrils which she uses to capture, impale and decimate her enemies. The tendrils are strong enough to hold transformed Garfiel in the air and incapacitate him. She is also able to slip the shadows into someone's body through wounds and disperse them outwards, effectively destroying the opponent from the inside out.
- In the instances in which she has appeared even though still sealed, just showing up has caused the entire area she was in, to be completely enveloped in Shadows. After covering the area in Shadows, Witch of Envy then began absorbing everything around her–the more she absorbs the more mass her vortex of shadows gains.
- By creating a veil of shadow over her person, Satella could seemingly nullify physical damage directed at her. Even the mighty blows of Garfiel Tinsel merely dissipated upon making contact with the Witch of Envy.
- In some instances, she can also be seen creating hands from her shadows, similar to the Unseen Hand that came from the Authority of Sloth belonging to Witch Cult's Sin Archbishop of Sloth Petelgeuse Romanee-Conti. She often used a shadow hand to grip Subaru's heart whenever he spoke about his ability to anyone who isn't her. According to Puck, Satella was capable of manifesting over two-thousand shadow hands at once. She can also make the hands go intangible. It is unknown if Satella's shadow hands are in any way related to the Authority of Sloth.
Time Manipulation: The Witch of Envy has the power to manipulate the flow of time to a certain extent. She can seemingly manually turn back time whenever Subaru dies. Whenever Subaru tries to speak about his Return By Death ability, Satella seemingly freezes time then squeezes his heart with a shadow hand so as to forcibly and painfully silence him. It is unknown whether this is part of her Authority of Envy or a completely different ability.
Magic User (魔法使い Maho Tsukai): According to Beatrice, the Witch of Envy is capable of using Yin Magic, as she attempted to use an advanced spell form that would have teleported Subaru, Rem and Louis to a different location, but failed. It was noted by Julius and Beatrice, that the spell was a clump of Yin Magic, more akin to an advanced version of Shamak that was given direction.
Miasma: The Evil Sealing Stone Shrine where Satella is sealed is covered in the Witch's Miasma, which is so thick that it distorts everything in one’s view. The Miasma invades the minds of anyone it touches, annihilates their flesh, and corrupts their soul. During one of the failed loops of Arc 6, Subaru, Ram, Anastasia and Patrasche fell victim to the Witch's Miasma, going mad and killing each other in a bloody spectacle of betrayal.
Great Power: In her era, Satella was one of the most powerful people alive whose defeat could only be attained by the combined efforts of the strongest heroes of the time. Among the Witches of Sin who were reviled by the world, Satella was easily the mightiest. If not for the interference of the Sage, the Divine Dragon, and the Sage's apprentice, Satella would have overwhelmed and defeated the first Sword Saint, despite the Sword Saint being stronger than her. Even within the modern era, the Witch remained almost completely unrivalled in terms of power. The only two individuals whose strength surpassed her own are the current generation's Sword Saint Reinhard van Astrea and his legendary ancestor Reid Astrea who contributed to her defeat four hundred years ago. According to the author, if Satella and Reinhard were to fight, it would end in a stalemate as she wouldn't be able to land a finishing blow whereas Reinhard couldn't bypass her immortality.
- According to the author, the meaning behind Satella's name will be revealed in the final arc.
- According to the author, Satella lacks common sense, and the situation is so serious that her dictionary doesn't even have the word common sense.
- In the anime, Satella received a redesign by Otsuka Shinichirou.
- The author once stated that Satella is the second tallest of the witches.
- Although Echidna initially stated that she and the other five witches were all killed by the Witch of Envy and "used them as sustenance", it is later revealed that their deaths, with the exception of Minerva, were uninvolved with the Witch of Envy. It is currently unknown if the Witch of Envy was actually involved with the other five witches' deaths in any way.
- Satella is the only Witch of Sin who wasn't succeeded by a Sin Archbishop (except for Pandora and Hector). This was likely because, unlike the other Witches, Satella didn't perish, meaning her Witch Factor wasn't inherited by anyone.
- Subaru has said the exact same phrase he said to Emilia in episode 1, to Satella at the end of the tea party, with the exact phrase being "I will save you no matter what". In Japanese:-『俺が、必ず――お前を、救ってみせる。』