Ardra posing as Satan in 2367.
Lucien
The Devil (also known as Satan or Lucifer) is a malevolent entity from Christianity as depicted in the Bible.
When Khan was exiled to Ceti Alpha V by James T. Kirk, he referred to a passage from Milton's poetic dramatization of the story of the Devil's fall from grace, Paradise Lost, in which the Devil states that it is "better to rule in Hell than serve in Heaven." (TOS: "Space Seed")
Lucien, an inhabitant of Megas-Tu during the 23rd century, had once lived on Earth, where he was known by the name Lucifer with his appearance becoming the basis for the Christian depiction of the Devil (TAS: "The Magicks of Megas-Tu"). Other religious characters resembling the biblical Devil are Fek'lhr and Ardra.
On Omega IV, an entity known as the Evil One was cast in the same light as the Devil. Captain Ronald Tracey, in violation of the Prime Directive, tried to trick the Yangs into thinking that Spock was the Evil One. (TOS: "The Omega Glory")
While demonstrating her abilities to Captain Picard and Lieutenant Worf, the impostor posing as Ardra also turned into the Devil and Fek'lhr. (TNG: "Devil's Due")
- The Devil (as seen in "Devil's Due") was played by Thad Lamey. Kang tells James T. Kirk that the Klingons have no devil, but are familiar with the ways of the Earth devil in TOS: "Day of the Dove".