Cypher was a corporate spy sent to to brainwash three business leaders and make them commit suicide if they get awarded a contract to a government's weapons project. Cypher nearly murdered Lucius Fox before being foiled by Batman, Robin, and Jean-Paul Valley. He was sent He was sent to Blackgate Penitentiary.
Later, he broke out of prison along with Clue Master, Electrocutioner, and Czonk. Cypher attempted to control them, however he was killed by Clue Master in the process. The reason that Cypher couldn't brainwash them was because they were wearing ear-plugs since Clue Master anticipated this.
Powers & Abilities
Cypher can hypnotize his victims using his precise voice. His mind control in conversation can only command his victims to sleep, however he can force the victim to do whatever he wants if his voice is heard passively.
In Other Media
Beware The Batman
In this version, Cypher is an agent for Ra's Al Ghul. In "Control", he took control of scientist Jason Burr to make him re-create his Ion Cortex project. Katana attempted to stop him, however she was brainwashed by him. Fortunately, Batman was able to free Burr and Katana, only to be controlled himself. Katana prompted Batman to break the mental link, allowing him to discover the link's weakness, and manages to defeat and arrest Cypher. At the end, however, Burr is still somehow controlled by Cypher and became a villain known as Kobra.