I am interested to know, after the death of Durin's bane by Gandalf, were there any Balrogs left in Middle-earth, or was it the last Balrog?

  • It probably was (seeing as Tolkien's final view was that there only ever existed 3-7 balrogs, and the odds of a second one having survived the War of Wrath is pretty small), but we don't actually know. – ibid Jun 21 '17 at 4:18