Of the many schemers that Edward "Ed" and Alphonse "Al" Elric encounter on their journey hoping to covet the powers of the Philosopher's Stone, Amestris' mighty military or other ends for themselves, these individuals truly distinguish themselves.
Original Manga and Brotherhood
- The Ishvalan warrior priest known only as "Scar" is hellbent on punishing the Amestrian State Alchemists who annihilated his people. Biding his time to corner and murder thirteen of them, Scar almost kills Ed twice and evades both Amestris and the Homunculi's attempts to take him down. When he discovers the Homunculi orchestrated the Ishvalan Civil War, Scar decides to counter their plans by finding the secret behind his brother's research, joining forces with Ed's group to free their friend Winry Rockbell from the corrupt Central command leaders, and activating the Ishval refugees' secret city-wide transmutation circle to boost the alchemists' powers. A resolved and introspective survivor, Scar gives up on his vengeful ways and accepts to join the military's efforts to rebuild the Isvalan nation alongside the reformed Amestris.
- The Truth, which also refers to itself as the World, the Universe or God, is the all-knowing personification of the Law of Equivalent Exchange and gatekeeper of the Gate of Truth and its power. Alchemists who perform human transmutation are taken to its realm, where the Truth forces them through the gate, giving them massive amounts of alchemic knowledge in exchange for being physically mutilated in a manner befitting the arrogance which led to their transmutation. The Truth does this to teach lessons and, upon Ed figuring out that alchemy isn't the answer to everything and sacrificing his own Gate to save his brother Alphonse, congratulates him and allows the brothers exit. Conversely, when Father absorbs the powers of God and is subsequently defeated, the Truth casts him into the Gate forever when it becomes clear that he never learned anything.
- Lust, one of the first Homunculi introduced, is a reserved and devious woman who uses Father Cornello as a proxy to sow discord and win over followers. After eliminating their failed pawn, Lust has fellow Homunculus Envy masquerade as him to continue their plans in the area and she herself begins handling information gathering in Amestris while seeing to threats eliminated, going undercover as "Solaris" to seduce Jean Havoc and gain information while also framing Maria Ross for Envy's murder of the intrepid Maes Hughes. Showing herself as a vicious and capable fighter, Lust comes close to even killing Roy Mustang, using the last of her life in dignified acceptance of her defeat while promising that Mustang shall one day know suffering. Though the first of her kind to die, Lust's meticulous planning skills and charming manipulations set up a character type to stand out in each iteration she has been presented in.
- Solf J. Kimblee is the "Crimson Lotus Alchemist" and a devious, cunning former Major in the Amestrian military. Ostensibly imprisoned for war crimes in Ishval after he purloined a powerful Philosopher's Stone, Kimblee showed both cruelty and compassion in the conflict, killing civilians a fellow soldier had spared before helping the soldier up and reminding him of their duty in the military. Released from jail to assist in Father's scheme, Kimblee shows ingenuity in his tactics: coercing Ed into assisting him; evading an attempt to assassinate him; and later causing the deaths that Father needs by convincing a military unit from Amestris' rival nation Drachma that he means to assist their attack on the Briggs fortress, only to lure them into a trap and use the Drachmans' blood for Father's ritual. Even after being devoured by Pride, Kimblee's spirit returns when the Homunculus attempts to cowardly forego his own haughty and boastful principles to take over Ed's body, forcing Pride to meet his fate while tipping his hat to Ed, happily seeing that the victory goes to the one with the strongest convictions.
- Lieutenant General Grumman is the silly, seemingly harmless commanding officer of East City who masks a truly ruthless ambition. Introduced congratulating Mustang for finally breaking Grumman's winning streak of nearly a hundred victories in chess, Grumman later becomes Mustang's benefactor in scheming a coup against the Amestris high command, using his troops to deliver messages and even successfully disguising himself as an elderly woman to fool potential spies. Grumman baits Fuhrer King Bradley into a trap that incapacitates him for the coming coup, only to then leave Mustang to handle the invasion of Amestris all by himself, planning to swoop in and paint himself as a hero should Mustang fail, thereby securing his own promotion and framing Mustang as a traitor in the process. Even when Mustang pulls off the coup, Grumman's tactical genius enables him to secure the position of Fuhrer for himself for years to come, during which he keeps tabs on potential enemies while nonetheless looking forward to the exciting future to come.
- "Fullmetal Alchemist": Isaac McDougal is the rogue "Freezing Alchemist". Haunted by the horrific war crimes of Amestris in Ishval and uncovering the truth of Central Command, McDougal desires to punish Central and cast down Fuhrer King Bradley. Crafting multiple transmutation circles across the city and killing any soldier who gets in his way while creating a series of distractions, McDougal is able to survive battles with Ed, his brother Alphonse, Alexander Armstrong and even Mustang before unleashing a wave of ice to converge upon Central, declaring he will judge Bradley and condemn him to a "frozen hell" for his sins.
- The Sacred Star of Milos: "Colonel Herschel", born Ashleigh Crichton, was once a young alchemist born in Milos until his family was driven out by the country's alchemist-hating people, his parents' killed by their power-hungry guard Lieutenant Atlas and his face mutilated by the monstrous man. Joining the Cretan military with a mask, Ashleigh rose in the ranks and plans to subvert Atlas' schemes and claim the Sanguine Star to remake the world. Easily outplaying and murdering his hated foe, Ashleigh comes within mere moments of victory before being stopped and when his sister Julia gives her leg to save his life, peacefully withdraws to atone for his actions.
- Lust retains her devious, manipulative personality while gaining an extended, sympathetic backstory. Created when a man attempted to bring back his dead lover, Lust operates with a devotion to becoming human and strings along alchemists in the hopes one will create a Philosopher's Stone for her to do so. Nearly succeeding with Ed, Lust betrays Dante to assist Scar, the brother of her creator, in the creation of the Stone, hoping to use it on herself. After being released from captivity by Dante to hunt down Ed, Lust betrays her master to assist the boy, using her own knowledge of alchemy to nearly kill fellow Homunculi Wrath and Sloth and even when she herself is mortally wounded, gracefully and philosophically ponders her nature before passing.
- The Ishbalan only known as "Scar" used to live normally until the Amestrian military instituted a genocide against his people. Years later, Scar decides to take revenge on state alchemists, who decisively ended the conflict, while crossing paths with Ed and Al, constantly fighting with and sparing them, eventually even bonding with them, especially Alphonse, as they remind him of his past. Discovering the real nature of his arm as an incomplete Philosopher's Stone, Scar decides to he needs to destroy the state military and travels to the war-torn city of Lior, where he leads and protects the civilians, creates a city-wide transmutation symbol and tricks the Amestrian soldiers to their deaths with the help of Lust, while the civilians evacuate. A survivor determined to succeed, Scar uses his last moments to save Alphonse and finish the transmutation, dying while thinking about the Elric brothers, his brother and his own guilt.
- "The Phantom Thief": The alchemist "Psiren" is a charming thief who spends her days as the kindly nurse Clara. Preemptively announcing her targets, Clara gets Ed to help her escape a trap by pretending to be using the money to save her hospital. Though lying, Clara is revealed to care for her town and brings it publicity, ending the episode by giving Ed information on the Philosopher's Stone and escaping custody.
- Live-action film trilogy:
- Original 2017 film: Lust is the acting leader of the Homunculi trio seen. Having Envy take the place of a priest they had been manipulating to rile up his followers, Lust also works to ensure no humans catch wind of their plans, killing a doctor and ordering a pursuer murdered to frame Roy Mustang for this purpose. Professing her disgust at her two human collaborators, Lust also shows her positive qualities in combat with the heroes, stating her care for her creator and protecting the injured Envy from Mustang.
- The Revenge of Scar & The Last Transmutation:
- Lin(g) Yao, 12th Prince of the Xingese Empire, is far more ruthless but no less charming than his original incarnation. Meeting the Elric brothers on a train being hijacked, Lin prevents them from saving the passengers, even having his bodyguard throw grenades at them, in the hopes to force them to teach him the secrets of immortality. Planning a coup to take power from his father, Lin allows himself to become a vessel for the Homunculus Greed and persuades Greed to help him, stopping the plans of the Homunculi leader and returning to Xing with a Philosopher's Stone.
- The Ishvalan known as "Scar" is a brutal but Sympathetic Murderer. Hating the State Alchemists for their genocide of his people, Scar outwits and kills several of them before facing down with Ed. During the second film's climax, Scar nearly tricks and escapes from the Elrics before being caught. Coming to understand the heroes, Scar joins them and uses his brother's research notes to aid in stopping the Homunculi, personally killing Wrath and ending the series ready to help build a new Amestris.
- Fullmetal Alchemist and the Broken Angel: This version of Colonel Roy Mustang is even trickier than his original counterpart. Seemingly betraying the Elric brothers to be thrown in jail by a corrupt General, Mustang uses their inevitable breakout as a diversion to outplay and arrest the General. Harsh yet fair, Mustang even fights Ed to prevent him from seeing a girl he had befriended as she passes away per her and her father's wishes.