Tim Marcoh

Tim Marcoh (ティム・マルコー, Timu Marukō), formerly the "Crystal Alchemist", was the leading researcher in the military's Philosopher's Stone creation project. After sacrificing a number of innocent Ishvalans during the Ishval Civil War to create new stones in Laboratory 5, he fled the military with some imperfect stone samples. He settles down in a small country town where he uses his stones to heal the sick under the identity of "Doctor Mauro". He is later found by the Elric brothers, and he directs them to some of the research he left behind in the National Central Library to help them in their search for the Philosopher's Stone. When first found by the Homunculi he is kept under house arrest, forced to stay put and alive or risk the destruction of his town. He is later taken into their custody to be used in their future plans, and is kept locked up deep below Central. While there, Envy takes great pleasure in tormenting Marcoh by constantly reminding him the Homunculi would massacre his hometown if he ever escaped. After some time as a prisoner, he is found by Scar. Seeing Scar as a means to an end, he tells the Ishvalan of his involvement in the Ishval Civil War in the hopes of being killed in vengeance. Scar, instead, only disfigures his face beyond recognition as a disguise, kidnaps him, and forces him to help in bringing down the Homunculi. While on the run, he is eventually discovered by Envy, who vows to take him back to Central but not before killing hundreds in a near-by village as revenge for Marcoh's escape. Knowing this, the Crystal Alchemist attacks Envy using his hidden transmutation circle to critically damage the Homunculus' core stone.

In the 2003 anime series, Marcoh plays a somewhat lesser role. After being taken into custody by Juliet Douglas, he is confronted by Lust. She questions him about the information he gave to the Elrics and subsequently murders him. His body is implied to have been eaten by Gluttony. Tim Marcoh makes a brief cameo in the penultimate episode as one of the forms Envy uses to toy with Edward.