Jean Havoc

Second Lieutenant Jean Havoc is one of Colonel Mustang's most trustworthy subordinates at the Eastern Headquarters and one of the few privy to the Colonel's goal of becoming Führer. A self-proclaimed 'country boy', Havoc is usually rather laid-back and almost never seen without a cigarette in his mouth, but is an honest, loyal and hard-working soldier who leads his own subordinates by example. Although not the most intelligent, Havoc more than makes up for his simplicity with common sense and cleverness - often providing a sarcastic, real-world perspective to counter the over-the-top antics of his comrades - as well as a particularly high combat aptitude. But the fair-haired son of eastern Amestrian merchants does have a noteworthy weakness: throughout the series Havoc's poor luck keeping a girlfriend plays a recurring theme, as shown when he is forced to leave a new relationship in East City when being transferred to Central with Mustang and when he is spurned by Major Alex Louis Armstrong's younger sister Catherine Elle.

2003 anime series
In the 2003 anime series, 2nd Lt. Havoc plays little more than a supporting role in the storyline, providing comic relief and backup alongside his comrades Heymans Breda, Vato Falman and Kain Fuery. Notable instances of Havoc's involvement include the point at which he and Master Sergeant Fuery are lightly wounded by ricochet fire while attempting to sneak up on Edward and Alphonse Elric near Resembool and his mission, near the end of the series, to act as a decoy for the Amestrian Military by disguising himself as Mustang during the Colonel's coup in Central City.

Manga
In the manga, however, Havoc plays a more significant role in the story, beginning in volume 9 with the Barry the Chopper mission to lure out the Homunculi. In Chapter 34, while Warrant Officer Falman is charged with standing guard over Barry, Havoc visits their safehouse in the slums, bringing additional weapons and provisions for Falman to use. He mentions to the two that he has finally found a new girlfriend in Central City named "Solaris", but she is revealed to be Lust posing as a human in order to gather information from him regarding Colonel Mustang's activities. Fortunately, Havoc reveals nothing vital or confidential about his work to her.

During the plan to extradite 2nd Lieutenant Maria Ross to Xerxes, Havoc acts on the scene, providing Roy with the false corpse and Ross' prison tags from inside a secret tunnel located behind a dumpster. Havoc then ushers Ross away through the same tunnel to rendezvous with Breda and Fu, mentioning that Edward Elric's arrival was an unforeseen hitch in the plan, but that the Colonel would work something out.

Immediately after Ross' safe passage out of the country, Havoc is assigned (under the codename "Jacqueline") to covertly surveil Falman's safehouse, with the support of Lt. Hawkeye and Master Sergeant Kain Fuery, in order to respond when the Members of the Ouroboros make their move to recapture Barry the Chopper. After three days of vigilance, "Jacqueline" is given the order to strike when Barry's reanimated body - sent by the Homunculi - arrives on the scene to eliminate Number 66. Havoc bursts into action to support Falman and Barry, dressed in covert ops gear and mask, but (though Falman was unaware of Havoc's surveillance) the Warrant Officer recognizes the 2nd Lieutenant due to the scent of cigarette smoke on his person.

Havoc drives Barry's body outside, where Hawkeye can offer them sniper support, and joins up with Colonel Mustang and Alphonse Elric in pursuing the two Barrys to Central Alchemical Laboratory Number 3. Jean and Roy venture deeper into the hidden reaches of Lab 3, which Havoc notes as having "the stink of violence", and are confronted by Lust, who reveals herself to be a Homunculus.

Though Lust manages to disrupt Roy's primary mode of combat by rupturing a water pipe in the room and dousing the Flame Alchemist's gloves, Havoc is able to aid Roy by providing a spark from his cigarette lighter after the Colonel transmutes the water into combustible hydrogen and flammable oxygen, creating an explosion that incinerates the Homunculus' body. But when the two get closer to investigate, Lust regenerates and impales Havoc through the abdomen with two of her bladed fingers, causing him to collapse and fall unconscious from the blood loss.

Roy is able to use fire to sear Havoc's wounds closed and staunch the bleeding and, after Lust is defeated, the two are brought to a hospital, where Hawkeye and Mustang discuss the current situation, what they have learned from the last mission and how to proceed in uncovering the truth. But Havoc states casually that they will not be able to count on him in the future, as he cannot feel either of his legs. Lust's attack in Lab 3 injured his spinal cord, paralyzing him from the waist down.

As it is unlikely that Havoc will be able to return to active service with his injury, he decides to accept a discharge from the military and makes plans to live as a civilian, helping out at his parents' general store in the eastern countryside. When Roy - feeling responsible for his friend and comrade's plight - hesitates to let Havoc give up, Jean explodes at him, demanding that the Colonel leave him behind and stressing that there is no time to waste pitying a pawn that can no longer move if Mustang is to reach the top. Roy begrudgingly complies, but states that he will be forging a path to the top on which he expects Havoc to catch up with him.

Havoc continues to work out his upper body from his hospital bed using small weights given to him by Breda despite protestations from his worried mother and declares that he will strive to catch up to the others, even from outside the military. When Führer King Bradley forcibly disbands Mustang's unit, scattering Breda, Falman, Fuery and Hawkeye, Havoc remains the only member of the team able to move and act freely. He is able to pass on Hawkeye's message regarding The Promised Day to Mustang before being transferred to an eastern hospital.

In chapter 89, during Mustang's attack on Central Command, 2nd Lieutenant Rebecca Catalina and 2nd Lieutenant Maria Ross arrive as backup in an armored truck disguised as an ice cream truck and positively laden with fresh ammunition and sophisticated weapons. When Roy asks who ordered them in to help and provided them with such equipment, Ross patches him in to Jean Havoc, who has been running a covert weapons trade under the cover of the Havoc General Store.

Trivia
Jean Havoc's character design is based off of the character "Jack" from Arakawa Hiromu's one-shot manga chapter Shanghai Youma Kikai. Additionally, Lust resembles the character "Miss Nynetales", Jack's boss from the series. Jean and Lust's relationship during the Fullmetal Alchemist manga appears to have been a reference to that project.