(Capcom's primary storyline)
Black dress Natalia is Natalia Korda's second personality and is the manifestation of Alex Wesker's personality in Natalia which was the result of Alex Wesker capturing her and transferring a digitized copy of her human consciousness into her, six months before Barry's arrival on Sejm Island. She is the much more darker and sarcastic of the two, and is characterised by her dark clothes and blonde hair.
Sejm Island and Transfer Procedure (2011)
Alex Wesker began her research into immortality at Lord Spencer's request back when she worked for the Umbrella Coporation, only to betray him after learning of the Wesker Project and realizing that she had no reason to obey someone who was, in her own opinion, a pathetic and delusional old man. She took all her research and resources and disappeared, taking up residence on the isolated Sejm Island where she ruled the community as its 'Master'. She would spend the next few years continuing her immortality research for her own purposes, both to save herself from an incurable illness she had developed and to spite the man who had manipulated her for most of her life.
Eventually Alex came to the conclusion that biological immortality could not be obtained and developed a new solution, and that was transferring a digitized copy of her human consciousness into another host. Through numerous experiments Alex determined that the vessel had two requirements; they had to be mentally strong enough to overcome any emotion of fear and required six months to safely stabilize the new consciousness. Alex immediately set out to find the person she needed.
To that end, she affiliated herself with senior Terra Save member Neil Fisher, who as one of former Federal Bioterrorism Commission leader Morgan Lansdale's supporters was looking for a way to bring back the FBC. She enlisted his help to procure a suitable human host in exchange for a sample of the Uroboros Virus that she had gained from fellow Wesker Child Albert Wesker, which he would then use to create a new terrorist threat to justify the FBC. She also received word from her Head Researcher, Stuart, that he would exterminate everyone who participated in their research once everything was completed, himself included, which he would accomplish a short time before the Transfer Procedure commenced.
In 2011, Neil prepared a list of potential candidates for Alex's experiment, and she sent her private militia to abduct Claire Redfield, Moira Burton, and other TerraSave members during a party. Neil was also taken so he could pose as a fellow abuctee to seek out the best candidate for the Transfer Procedure. All the candidates were taken to Sejm Island to be used as test subjects for t-Phobos, where they were placed in random locations and fitted with special bracelets that changed colour in response to fear, such as the one Alex herself wore. Alex also used the bracelets to communicate with the candidates, frequently taunting them, directing them to locations redesigned to test them and quoting various works of Franz Kafka, her inspiration. Each candidate was injected with the t-Phobos virus, which was designed to trigger and mutate the host should they lose control of their fear.
Several candidates inevitably died during the experiment, including Gabriel 'Gabe' Chavez, Gina Foley and Edward Thompson, and at least one candidate called Pedro Fernandez succumbed to fear and mutated. Claire and Moira would prove to be resilient and tracked Alex down to the tower where she resided. Despite this, the experiment succeeded and Alex found the vessel she needed. Among the candidates was an ophan child named Natalia Korda, who Neil had rescued from the Terragrigia Panic that Lansdale had instigated several years ago. The intense trauma she suffered during the incident had left her incapable of feeling fear, as proven when her bracelet turned red and she suffered no effects from the virus. With Natalia confirmed as an ideal vessel, Alex sent Neil bring the girl to her to begin the Transfer Procedure. Neil seized his chance when Gabe tried to escape the island with a helicopter he had repaired, only for Alex to remotely sabotage the vehicle's controls. While Claire and Moira were watching in horror as the helicopter crashed, killing Gabe, Neil quietly stole Natalia way and took her to the tower.
Alex and Natalia spoke for a short time before Natalia was sedated and placed in a special glass pod in Alex's private laboratory at the very top of the tower, and Alex went down to the surveillance room where Neil was waiting. When Neil tried to make Alex hold her up end of the deal and hand him a sample of Uroboros, Alex gave him what he wanted by shooting him with a virus-filled dart. She proceeded to taunt him with his failed aspirations before leaving him to mutate, returning to her lab to begin the Transfer Procedure. Neil managed to take the elevator down to the bottom of the tower where Claire and Moira discovered his betrayal and defeated him.
Once preparations were complete, Alex activated a platform beneath Natalia's pod and sent her down to the bottom of the tower to begin her six month long hibernation, then prepared to commence the 'final threshold' that she had to cross. Minutes later, Claire and Moira reached the lab and confronted Alex, separated from her by a large pane of thick glass. Unfazed that they had reached her, Alex gloated over her accomplishment, pulled out a gun, and shot herself in the head, seemingly killing her old self she could live on within Natalia. The upper spire of the tower soon after self destructed in response to her death. Claire managed to escape the explosion and the island, but is forced to leave Moira behind when she ends up trapped beneath fallen debris on the other side of a collaped walkway.
Dark Natalia Awakens (2011)
The six months pass and Natalia awakens, emerging from the pod to find herself in a strange lab room. It was here that 'Dark Natlia', a manifestation of Alex's transferred consciousness, appeared to Natalia and claimed that she also is Natalia. Having been separated from her bear, Lottie, before being placed in the pod, Natalia was anxious to find her. Dark Natalia presented Natalia with a postcard supposedly from Lottie and suggests that they go find him.
Following directions within the postcard, Natalia and Dark natalia began their search in the sewers beneath the tower, where they encounted Revenant. Dark Natalia aided Natalia by using her ability to 'see' the monsters, and the fact that the monsters could not see her. They sneak past the monsters and find another postcard directing them to a tunnel nearby the town. As they continue their search, Dark Natalia repeatedly suggests that they leave Lottie behind and mocks Natalia that the reason she is always alone is because she is with a "stupid bear". Natalia doesn't listen, as Lottie has been her only friend since she lost her parents. They eventually find another postcard leading them further out towards the island's coast, where they find themselves avoiding Glasps as well as Revenant. With the increased danger, Dark Natalia recommends that Natalia lets her take control to make things easier. To Dark Natlia's frustration Natalia refuses, not fully trusting her doppelganger.
A final postcard leads them to the beach where they finally find Lottie. To Natalia's shock the animated bear curses at her, furious that Natalia had won their game of 'tug and war', before laughing and falling limp. The search for Lottie had in fact been a trick to make Natalia allow Dark Natalia to take control of her body. Dark Natalia picks up the bear and tells Natalia that she still has time to get under Natalia's skin and in Alex's voice, promises that next time, Natalia won't see her coming. She then vanishes with Lottie, leaving Natalia alone on the beach where she soon encounters Barry Burton.
Dark Natalia remains dormant during Natalia and Barry's journey through the island while Natalia gains her ability to 'see' the monsters. When they return to the tower in search of Moira, they discover that the bottom of the tower has been completely decorated in dozens of naked and mutilated dolls, and that the original Alex is still alive but in a horrifically mutated state. She had felt a moment of pure fear right before her suicide, and that fear triggered the virus in her body and revived her as a monster. Driven mad by the thought of a second Alex existing, Alex has devoted herself to destroying Dark Natalia before she could fully awaken in Natalia. Though Barry and Natalia escape the tower, Alex managed to track them down near the mines, knocking Barry over a cliff before starting to strangle Natalia. Initially Natalia seems helpless, but then has a sudden change in demeanor, terrifying Alex into releasing her and fleeing. Though ambiguous, it appears that Dark Natalia has temporarily surfaced and scared Alex away.
In the Bad Ending, Dark Natalia finally succeeds in taking over Natalia's body when she and Barry confront Alex in a laboratory beneath the underground research facility. Having injected herself with Uroboros in a last ditch attempt to destroy Natalia, the empowered Alex knocks Barry aside and grabs Natalia, squeezing her into unconsciousness. This unintentionally gives Dark Natalia the chance to take control, and she awakens with glowing red eyes. With superhuman strength she proceeds to dismember the hand crushing her before ripping out Alex's core, killing her. When a stunned Barry confronts her, Dark Natalia tells him to call her Alex and begins to leave. Realizing what had happened, Barry aims his gun but can't bring himself to kill the girl he had grown attached to, to which Dark Natalia taunts him before disappearing.
In the Good Ending, Moira appears and shoots Alex, saving Natalia and preventing Dark Natalia from surfacing.
Post Sejm (2013)
"A Cage went in search of a bird. But now the bird is gone. The bird has changed"
— Natalia while reading The Zürau Aphorisms
Dark Natalia can be used in Extra Episode: Little Miss alongside Natalia Korda. She is invisible to any types of enemies in Resident Evil: Revelations 2. She can show Natalia the location of an enemy by pointing at it. Though, she can only point at them one at the time. However, she cannot open doors or obtain any items.
Also in Little Miss, Dark Natalia has unique voice lines tied to the Partner Action Button where she will order commands or reply to Natalia in a more cocky manner. In the main campaign, Natalia has a "Black Dress" outfit which changes her look to that of Dark Natalia's, though the gameplay remains the same, including the default voice lines.