The Bible refers to the "devil and his angels."  And, Satan, the Devil, or Lucifer is referred to as being the King of the Bottomless Pit in Revelation 9.  Satan is the One who ascends out of the Bottomless Pit, first, in Revelation 11 to overcome and kill the Two Witnesses, and, second, is the One who deceives an unsaved world in Revelation 17.  He empowers the Beast or Antichrist.