Wolfenstein
The "Wolfenstein" series of video games started with the 1981 stealth-adventure video game "Castle Wolfenstein". It was developed by American programmer Silas Warner, a pioneer in the early eras of video gaming, especially the stealth genre. It was published by his (then) company M.U.S.E. Inc. (Muse Software). The player controls an unnamed American prisoner of war as he steals war files containing information about secret German war plans while avoiding or sometimes killing guards, and tries to escape the fortified Nazi stronghold Castle Wolfenstein, set during World War II. The game is often credited as one of the first video games of the stealth genre, since it focuses more on avoiding or disarming enemies, and killing them is considered a last resort.
Cyberdemon
In the action role-playing game "Doom RPG", the Cyberdemon is created by an occultist scientist Kronos. In "Wolfenstein RPG", the Cyberdemon appears as the Harbinger of Doom, summoned by the Nazis at Castle Wolfenstein during World War II. American commando William "B.J." Blazkowicz defeats it using the Spear of Destiny, destroying its right leg and left arm, and the Harbinger vows that it would have a rematch with Blazkowicz's descendent in the future, which happens when Stan Blazkowicz faces it in "Doom II RPG".