Master Berthold Hawkeye was both the alchemist who mentored Roy Mustang as well as the estranged father of Riza Hawkeye. A brilliant alchemist, Hawkeye postulated the complex and intricate theorems necessary to apply flame alchemy at its most powerful and efficient level, but refused to pass on his flame alchemy secrets to his pupil, thinking them too dangerous for young and naive Roy. Riza describes her father as a frightening man with whom she did not generally associate and could not at all relate. Afraid of his life's work being destroyed and what his Flame Alchemy knowledge could do if it fell into the wrong hands, Master Hawkeye refrained from keeping notes in the normal fashion and, instead, tattooed a large Transmutation Array containing the culmination of his craft and findings on his daughter's back, perhaps further straining - or serving as an indication of - the Hawkeyes' already shaky relationship. Master Hawkeye, as an independent alchemist, appears to hold some disdain for the State Military (much like Izumi Curtis), as revealed by his flippant reaction to Roy's enlistment during the Ishval Civil War as well as his preference of living in squalor with all his genius over joining the State Alchemist Program. As Roy returned to his teacher's house in an attempt to get hold of the theory of Flame Alchemy to enlist as a State Alchemist (he was just a regular soldier at that time), Master Hawkeye revealed to him his daughter possessed the theory and succumbed to illness, coughing up blood as he died in Roy's arms. (Source: Fullmetal Alchemist Wiki)
A chimera that follows Greed. He was fused with a bull, making him as strong as one, as demonstrated to Al when he literally knocks Greed's head off with his hammer (Greed, naturally, recovers from this). He wields a hammer as his weapon and has an ability to transform into an enhanced version of himself with more bull-like aspects like horns and greater strength. He's the only one of the three that fought in Ishval. He cameos in the 15th volume, shown as a background soldier, after Roy Mustang's appearance in the battle ground.
Denny Brosh is the partner of Maria Ross. He is rather nosy and lazy, and has an enormous infatuation with his partner. He is very sensitive to criticism, and will fall into despair at the slightest insult. Both he and Ross are introduced when they are assigned to protect Edward Elric.[77] In the anime, Brosh later appears in the rebellion against King Bradley, saving various characters from execution. In the manga, he appears again after Ross's apparent death. Though he is deeply saddened by the news, Ross feels it is for the best that he not know she is alive, as he has difficulty hiding his emotions. When Roy Mustang begins waging an assault on Central, Brosh rushes into the city to provide assistance. (Wiki)
Brigadier General Basque Grand (the Iron Blood Alchemist) is an ambitious alchemist known for going to any lengths to complete an assignment. His alchemy title refers to Grand's ability to transmute the iron in his blood to an assortment of guns and other weapons. Grand was also in charge of the "defunct" Laboratory 5 in Central, which he ran in hope of creating a philosopher's stone for his own purposes.
Truth is the most commonly used name for the mysterious and ethereal being that sits before The Gate and addresses alchemists who have stepped into God's domain through the use of alchemy. It appears as a pure white, nearly formless being almost indistinguishable from the rest of the endless white expanse which surrounds the Gate but for a shadowy outline which causes Truth to reflect the shape of the person it is talking to, thereby supporting its claim to be another shade of that very person. When Edward and Alphonse Elric each appeared before the Gate, Truth took on the shape of a young boy and when Izumi Curtis appeared, Truth's shape reflected that of a young woman, appeared as a vigorous man to Roy Mustang, and a white version of Father's flask form. Truth initially introduces itself as the being some people call God, the World or the Universe, at first seeming welcoming and jovial to its guests before calling attention to their hubris and opening the Gate, which forces them inside. At this point, Truth often smiles with an eerily wide and insane grin that is similar to that of the Homunculus Gluttony and Father. When the alchemist in question returns from his or her sojourn through the Gate, Truth informs them of the necessary toll for accessing the Universe's knowledge and collects it, usually in the form of a body part which disintegrates off the alchemist and reappears on Truth's form. In this way Truth is responsible for the taking of Edward's left leg and right arm, some of Izumi's internal organs, Roy's eyesight, and Alphonse's entire body. It would appear that Truth's goal is to discourage humans from treading in God's domain, as it calls Edward a fool when the young boy returns and sacrifices his arm to recover his brother's soul. (Source: Fullmetal Alchemist Wikia)
Neil is one of the chief engineers in the Research & Development sector of Fort Briggs. While privy to all the mechanical goings-on in the fort, Neil is especially knowledgeable on the subject of cold-climate metals such as those used in North Area automail limbs and is often seen acting as Captain Buccaneer's automail mechanic. A laid back and easygoing fellow, Neil is quick to make friends with those who come to the fort and is even more eager to share his expertise on the technological advancements the facility has made.
A butcher who uses the disguise of a female so he can abduct women. Manga: A wanted serial killer and later an experiment in 5th laboratory. He falls in love with Riza when she was out grocery shopping in vol. 7. By that, he was caught by the military. He later helped Maria Ross escape from prison. In the original anime, he goes after Winry, but Edward eventually gets the best of him. He was seen arrested, but later reappeared as a soul bound to armor. "I kill, therefore I am." ~ Episode 21