Dr. Josef Melikus (also spelled Merekes or Merikus) is a German scientist of Jewish descent affiliated with Talon. A recognized authority in cybernetic engineering, he leads Talon's cyborg division, overseeing cybernetic weapon development and deployment. This includes creating and enhancing the esper cyborg soldier Sonnet Barge and the prototype RX-606, later known as Bird.

Melikus recruits Sonnet after her traumatic experiences in New York slums, where assault and forced prostitution triggered violent manifestations of her latent psychic abilities. He transforms her into a cybernetically enhanced operative for Talon, designing her body specifically to harness and control those powers. Initially cold and calculating, Melikus prioritizes mission objectives, authorizing lethal measures like ordering Sonnet to eliminate a nurse who discovered her nature and orchestrating life-threatening "accidents" to provoke Lan Komatsuzaki's esper abilities.

Over time, Melikus develops a growing parental attachment to Sonnet, complicating his allegiance to Talon. This shift leads him to reluctantly agree to her requests to spare individuals, such as preventing the killing of Dr. Onagara and his family during Lan's abduction. His deepening paternal affection ultimately conflicts with Talon's directives, contributing to his professional and personal unraveling.

Melikus travels to Japan to personally oversee Sonnet's mission, collaborating with Talon subsidiary Azumi Industries. He participates in Lan's capture and her subsequent confinement in a laboratory where Talon attempts to clone her esper abilities through forced ovum extraction and surrogate implantation. His arc concludes without full resolution in the OVA, leaving his ultimate fate ambiguous amid the ongoing conflict between Talon and its adversaries.