<P> The entity referred to most frequently as The Man in Black (referred to as The Smoke Monster by the main characters) is a fictional character and the main antagonist on the American ABC television series Lost . He appeared primarily as a cloud of black smoke ("The Smoke Monster") until the final episode of season five, where he appeared as a middle - aged man dressed in black . In season six, he primarily appeared in the physical form of John Locke . He exhibited the ability to "scan" the minds and memories of others, allowing him to confront characters such as Mr. Eko and Ben, with "judgment" (a replay of their pasts), and to assume the forms and memories of the deceased, starting with the original Man in Black himself, being Jacob's brother, or Christian, Yemi, Alex, and Locke . According to Jacob, who explains this to Richard Alpert (Nestor Carbonell), it is the incarnation of evil, and its primary goal--to escape from the island--would be the "end of everything good". </P> <P> Various other characters have implied that his escape would be catastrophic and could even cause the destruction of reality . A longtime resident of the island that serves as the main setting of Lost, the true nature of the Man in Black was long shrouded in mystery . It had been described by Lost producer Damon Lindelof as "one of the biggest secrets" of the mythology, and the producers have often hinted that the black cloud of smoke was not a monster in the traditional sense . TV Guide included him in their 2013 list of The 60 Nastiest Villains of All Time . </P> <P> The Man in Black's earliest chronological appearance occurs in the sixth - season episode "Across the Sea", which depicted his birth on the island to a woman named Claudia (Lela Loren), whose ship wrecked off - shore . An unnamed woman on the Island (Allison Janney) delivers him and his twin brother Jacob but killed their mother and raised them herself . Jacob is swaddled in light cloth, while the Man in Black in dark . The woman raises the twins to be ignorant of a world beyond the island and of death itself . She also raises them to be distrustful of humanity, whom she regards as corrupt and dangerous . At age thirteen, the twins discover the other survivors of Claudia's ship on the island, and their adoptive mother takes them to a mysterious cave filled with light with a stream running into it . She tells them it is "the heart of the island", and one day they will be its caretakers . Soon after, Claudia's ghost appears to the young Man in Black, and tells him the truth . After he confronts his adoptive mother with this, he leaves to join Claudia's crew . Jacob visits his brother at the survivors' camp at various points over the course of the next 30 years, during which time the Man in Black comes to believe his mother was right in calling humanity inherently corrupt . Despite this, he stays with the crew, because they are a means to his finding a way off the island, which involves their use of the island's strange electromagnetic properties . When the woman learns this, she appoints Jacob as the new caretaker of "the heart of the Island ." She then visits the Man in Black at the bottom of a well, where he is planning to install a wheel to enable his use of the energy to leave the island . She knocks him unconscious, and then apparently massacres the people in the camp and destroys the well . Enraged, the Man in Black kills her with a dagger . Jacob retaliates by beating his brother and throwing him in the stream leading down the tunnel of light . A cloud of black smoke then emerges from the cave, suggesting it is the Man in Black's consciousness . After a while, Jacob finds the Man in Black's body in a pool nearby, and places it in a cave with his adoptive mother's corpse, along with a pouch containing the black and white stones they used in their game as children . It is consequently suggested that the black smoke's ability to take shape of dead people on the island led it to adopt the Man in Black's shape . </P> <P> The next chronological appearance of the Man in Black and Jacob was in "The Incident", in which they talk on the beach as the Black Rock ship approaches . The Man in Black (who looks like his real form) states that he knows the ship was brought by Jacob, and expresses his disapproval of Jacob bringing people to the Island--stating that all they bring is corruption and destruction . The Man in Black tells Jacob he wishes to kill him, but their adoptive mother had prevented the Man in Black from hurting Jacob, so he sought a "loophole" to kill him . Soon after, the Black Rock crashes onto the island, the Man in Black appears as the smoke monster and kills everyone on board except Richard Alpert (Nestor Carbonell). He then returns in the form of Isabella, Richard's dead wife, telling him they are in hell, and tricks him into thinking that Jacob has taken her, letting Alpert know that he is the "smoke monster" but could not save Isabella from Jacob . Later, in the Man in Black's form, he frees Richard and gives him a knife to kill Jacob, whom the Man in Black refers to as "the devil ." However, Jacob convinces Richard otherwise . Shortly after, Jacob visits the Man in Black and states that as long as he (Jacob) is alive, the Man in Black will never leave the Island . The Man in Black then vows to kill Jacob and his subsequent replacements . </P>

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