Amaterasu

was a survivor of the Great Cataclysm. Possessing an Adolla Burst, she powered Tokyo and was referred to as the.

Appearance
Amaterasu appears as a naked woman of slender yet curvy build with shoulder-length blonde hair, blue eyes who is regarded as resembling her counterpart Iris in appearance. Before being placed inside the Eternity-Style Thermal Power Generation, she is seen wearing a wore simple, baggy clothes.

Personality
As shown when she took control of Shinra, Amaterasu showed very manipulative behavior. She used his resentment towards people branding him as a Devil, his anger at the Demon that destroyed his family and his confused emotions about the Infernal's true identity to control him. Amaterasu's palpable hatred of humanity is felt by Shinra and noted by Haumea. Her volatile and misanthropic nature attitude fits with her status among the Eight Pillars, as she is considered the Pillar of Madness. While she controlled Shinra, Amaterasu tried to provoke him into burning and killing everything and everyone in their path. It's implied her intense hatred of mankind is the result of being forcibly used for centuries as a power source to restart civilization and start the Tokyo Empire after her Adolla Burst was awakened by the Evangelist.

Background
Soon after the Great Cataclysm, Amaterasu was found by Yona. Intending to use her Adolla Burst to make civilization bloom again, he encased her in a container and delivered her to Raffles Smith's group in disguise, leading them to use her as nourishment for the people and generating power for the Eternity-Style Thermal Power Generation "Amaterasu". During the construction of the Generator a member of the Joseph clan would hear the girl's voice begging for help. In their panic the Joseph family would hide away the Key to Amaterasu, a 'spell of destruction' that the Great Cataclysm's effect on physics made functional. While the conflict over this key would rage between the Joseph clan and Giovanni for centuries, Amaterasu's suffering would be either forgotten and ignored. And despite the generator being intended to cause the next Cataclysm, the clueless Tokyo Empire would come to see the Amaterasu machine as a blessing that guides them towards the light.

Abilities
As the First Pillar, Amaterasu possessed an Ignition Ability and an Adolla Burst. Shinra Kusakabe suspected and later confirms that she is indeed the power source of the Amaterasu that powers the entirety of the Tokyo Empire, further alluding to her immense power. Like the Woman in Black within the Tabernacle, she could appear before other Adolla Burst users through the Adolla Link. While she did not display her abilities in combat, Haumea would absorb her powers while inside Adolla, calling it her 'Light of Madness' and unleashing colossal explosions resembling nuclear blast. Escaping attacks of this scale required the use of Severed Universe.

Netherworld arc
When Shinra Kusakabe sleeps before his journey into the Netherworld, the woman appears before him in a dream. He is momentarily awakened by a small earthquake and is confused by the dream, believing that the woman was Iris.

VS. Special Fire Force Company 4 arc
Upon Shinra meeting Sōichirō Hague, the woman connects with Shinra through the Adolla Link, telling him kill Company 4's captain and to let the anger he once directed at the Demon explode before he snaps back to reality. When a controlled Karin interrupts Shinra conversation with Sōichirō to kill him, the woman appears once again. She seemingly taking control of the young officer with the Adolla Link, planning on using his anger to murder the other officers. This leads to them fighting Captain Hague, who successfully manages to force the rabid Shinra outside. While the battle continues, she promises Shinra that they will kill anyone who gets in their way. The battle seems to be in the Adolla pair's favour, until Arthur and Ogun intervene.

While Arthur senses her presence, the knight cannot free Shinra from her control. Arthur, Ogun, Hague and Pan all move to engage the possessed Shinra, ultimately Arthur continues the battle alone. She tells Shinra not to worry about being a hero or a devil, offering to give the boy information about his mother, if he is willing to kill his opponents. During the battle, Arthur is able to counter Shinra's confused arguments for becoming a Devil much to the woman's fury. This fury presses her and Shinra rushing in to finish Arthur, who counters with a barrage of strikes before finally telling Shinra to embrace being a hero once again to protect what he loves. The woman once again pushes Shinra to kill the Knight, claiming that being a killer is much simpler than losing those you love, but Shinra manages to break out from her control. Despite being disappointed by Shinra's unwillingness to kill, she enjoyed their meeting. While refusing to tell Shinra about his mother, the spectre says she will now play with the fifth and latest person to awaken the Adolla Burst.

Fifth Pillar arc
While Inca discusses her love of danger, the woman appears to tell Inca that she'll soon face a danger so great it will make her fall in love. Inca turns to confront the spectre but she disappears. She also appears to tell Shinra that the Fifth Pillar has awakened.

Chinese Peninsula arc
While investigating the Tear in Space, the joint investigation team from the Tokyo Fire Force discover an Oasis in Xinqin Dao Forest that has a generator identical to the Amaterasu generator in Tokyo. When Shinra's temper flairs up during the investigation an image of the blonde woman appears in his mind, Arthur chides him and reminds Shinra not to lose control again. The investigation into the Amaterasu-style power plant, the Tabernacle, uncovers evidence of human sacrifice and exposes the truth that a living being is inside it generating energy through their Adolla Burst, something Joker and Licht had perviously theorised about.

Vs.Holy Sol temple arc
During Shinra's journey back to Tokyo, he sees her in his dream. Believing that she is crying amongst flames hot enough to evaporate her tears, he asks if she is inside the Amaterasu power plant. The woman simply gives him a deranged smile and he wakes up, deciding to use Amaterasu as a name for this mysterious woman'. While Company 8 report that there is a human being exploited as a power source for the Tokyo Empire. Something that runs counter to the Holy Sol's teachings and throws the role of Vulcan's family in the machine's creation. Iris has a strong reaction to the revelation, immediately feeling immense sympathy for Amaterasu. Despite their reports and evidence, the Fire Force are told information about Amaterasu will not be made public until the government has verified the information. While he does not encounter her, Benimaru later notes in his attack on the Holy Sol that he dislikes the Amaterasu's energy, claiming he can sometimes feel bloodlust from the machine.

Haijima Industries arc
Gureo Haijima admits in a private conversation with Shinra, Licht and Obi that he is well aware of Amaterasu's suffering within his company's power system. He considers it a necessary evil that allows the Empire to thrive. In fact his only concern is finding additional sources of the Adolla Burst to research and add as a second source of power for the Thermal Power Generator. Shinra is outraged by this callous disregard for human life and Vulcan angrily vows to create a method of energy production that will not cause anyone misery.

Iris arc
While Shinra carries her and their bags back to Company 8's cathedral, Iris thanks him for his support and promises to tell him the next time she is worried about something. Shinra looks at her and is reminded of her resemblance to Amaterasu, the similarity disturbs him but he does not share this concern with Iris.

Stone Pillar Arc
A number of strange things happen as a result of Adolla moving closer to the reality every time a Stone Pillar raises from the sea. More Infernals appear and pyrokenetics have become more powerful as well. This growing power causes Iris to realise she had unknowingly possessed incredibly weak Third Generation abilities for years. As her powers grow Iris develops a feeling of discomfort: the feeling she is copy of another person. When she tried to approach Shinra about it, unfortunately his consciousness have been usurped by his Adolla counterpart and it lashed out at her for being 'here' as well. Once the real Shinra returns he is deeply apologetic about his other self's actions. Iris' feelings, her resemblance to Amaterasu and his experiences with doppelgängers cause Shinra to realise something. That Iris' personality is exactly what the entire empire believes Amaterasu to be like and that she is actually a doppelgänger of the First Pillar.

Trivia

 * There are several characters in Fire Force whose names are allusions to or directly taken from both monotheistic and pantheistic religions and notable religious figures.
 * Amaterasu is named after a major deity of the Shinto religion. Amaterasu is the goddess of the Sun and Universe.
 * Amaterasu's real name from before the Great Cataclysm remains unknown. She is only referred to as 'The First Pillar' or 'Amaterasu'.