Kain Fuery

Master Sergeant Kain Fuery is an Amestrian soldier originally stationed at the East Area Headquarters in East City and one of Colonel Roy Mustang's most trusted subordinates, hand-picked by the Colonel for his abilities and qualities. Sergeant Fuery is an expert with communications and surveillance equipment and states that his childhood hobby of tinkering with radio technology grew into a career when he joined the Amestrian military, as his superiors recognized his talents. Throughout the series, it is apparent that most of Fuery's usual duties involve fixing radio and telephone equipment and laying communication cable. Kain is a very kind individual as well, nearly always wearing a smile on his bespectacled face. This is earliest displayed when Fuery found a small puppy out in the rain and went out of his way to make sure it found a good home instead of leaving it where he found it. Mustang specifies that he chose Fuery to serve under him because of the way the young soldier took care of his own subordinates. Kain is often a cheerful and optimistic source of support for the other members of Mustang's unit as well as the Elric Brothers and, despite his timid appearance and limited combat experience, is hardly a novice soldier.

2003 anime
In the first anime series, Fuery plays little more than a small supporting role in the storyline, providing comic relief and backup alongside his comrades Jean Havoc, Heymans Breda and Vato Falman. Notable instances of Fuery's involvement include the point at which he and 2nd Lt. Havoc are both 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 Riza Hawkeye during the Colonel's coup in Central City. In the movie Conqueror of Shamballa he is seen near Sciezka in a diplomatic hall.

In the manga
Kain Fuery's role is a bit more significant in the manga's storyline, beginning in volume 9 with the Barry the Chopper mission to lure out the Homunculi. After Barry catches the attention of the enemy by absconding with 2nd Lt. Maria Ross, Fuery is assigned (under the codename "Kate" ) to covertly surveil Falman's safehouse from his nearby secret second apartment and relay information between "Elizabeth" (Riza Hawkeye) and "Jacqueline" (Jean Havoc), who are both positioned to strike should Fuery notice the presence of suspicious activity. When Gluttony attacks Hawkeye in her sniper tower, Fuery rushes to her aid with Black Hayate, providing cover fire and extra armaments for the Lieutenant to use, though Mustang appears to rescue them when guns prove useless against the Homunculus.

In Chapter 52, when Führer King Bradley forcibly disbands Mustang's unit, Master Sergeant Fuery is the first in the team to receive his reassignment papers from Central Command and relays the information about Breda and Falman's sudden reassignment to Lt. Hawkeye just before her own orders arrive. Fuery is sent to the Southern Area Headquarters, where (as revealed in Chapter 78) he is forced to dodge shellfire laying communication cable in the the front line trenches of the current border war with Aerugo in the town of Fotset. Though surrounded by death, Fuery steels his resolve and survives long enough to desert the military and rendezvous covertly with Mustang, Hawkeye and Breda in Central City in chapter 85.

Fuery participates in Mustang's coup d'etat battle in Central City, performing admirably in the field, and his communications expertise is instrumental when Mustang's unit takes over the Capitol Radio station in a bid to control the flow of information to the public.