Syrus

From Memory Alpha, the free Star Trek reference.

Syrus was supposedly a psychiatrist on the planet Tilonus IV. He worked at the Tilonus Institute for Mental Disorders. In truth, Dr. Syrus did not exist but was simply a character in a brainwashing scenario devised by Suna with the final purpose to gain tactical information from Commander Riker. (TNG: "Frame of Mind")

Syrus was played by David Selburg.