Lujon

Lujon is a character exclusive to the 2003 anime series. He is first introduced as a struggling young doctor in his small town studying medicinal alchemy in the hopes to cure a local plague called the "Fossil Disease" and also has a connection with Lust. At one point he was discovered by Lust, who, affected by memories of her original human counterpart with her lover and Lust's own creator thanks to Lujon's similarities to the man, taught him more advanced forms of alchemy and gave him a fake Philosopher's Stone to help him cure his townspeople.

He'd been engaged to a woman named Lydia, but while Lust helped him he was also falling in love with her, which Lydia noticed as she watched the two working together. Lydia was set to marry Lujon once her fossilization was cured, but on their wedding day, he left Lydia at the altar and confessed his love to Lust. Lydia rushed off after him and saw him embracing Lust, then stormed off angry and heartbroken; Lust, knowing she couldn't stay with Lujon, told him to leave after Lydia.

Sometime after the Homunculus left his side, however, the stone's power slowly began to fade and the fossil disease returned, causing him to flee in search of a new one. After some time, he finds Lust again as he'd secretly hoped, and she is quick to replace his old Red Stone for her own gains. When they finally return to town, he confesses his love for her once again; however, she's only brought back a little of her memories of her birth as a homoculi. He's shocked when she coldly kills him. Before dying, she states that he was her mistake (as she and Envy had been hoping for him to become astute and desperate enough to seek the creation of a real Philosopher's Stone) and nothing more. His stone breaks and his body becomes fossilized from the disease that then kills everyone instantly in town. Lydia, returning to town with the Elric brothers and Winry Rockbell, finds him and becomes fossilized in his arms.

Trivia

 * Lujon's behavior reminds Lust of Scar's brother, who is both the Alchemist who made her and the lover of the person she was meant to replace. Ironically, Lujon's seiyū, Takehito Koyasu, went on to voice Scar's brother in the 2009 anime, where he is a much different character.
 * At one point after Lujon has used the Stone that Lust first gave him to cure Lydia, Lust meets with Envy, who had disguised himself as an old wagon driver.  The pair talk about their plan, and Envy states that "Fossil Disease" was generated by the homunculi as part of the hope of fostering the kind of desperation that might lead a talented alchemist to desire the true Philosopher's Stone.