Doom (1993 video game)
Because id planned to self-publish the game, as the game neared completion they had to set up the systems to sell the game. Jay Wilbur, who had been brought on as CEO and sole member of the business team, planned the marketing and distribution of "Doom". He felt that the mainstream press was uninterested in the game, and as id would make the most money off of copies they sold directly to customers—up to 85 percent of the planned US$40 price—he decided to leverage the shareware market as much as possible, buying only a single ad in any gaming magazine. Instead, he reached out directly to software retailers, offering them copies of the first "Doom" episode for free, allowing them to charge any price for it, in order to spur customer interest in buying the full game directly from id.
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".