Possibilities:
-things come "full circle", everything starts to make sense
-there was a circle in the Fear Revealed logo
-"A new terror born", an all new icon
-the icon is a child or baby
-"A new terror born in death", reversed life (Benjamin Button)
-"death", the grim reaper is the icon
-"a new superstition", something we haven't seen before
-"superstition", black cats (Cats N' Combs)
-"unassailable", synonyms: hallowed, holy, inviolable, sacrosanct, sacred, untouchable
-"fortress". Medieval castle
-"forever", HHN will be forever changed
-quote from I Am Legend book, the character from the film looked similar to the Dogs of War
-quote from I Am Legend book, perhaps an apocalypse or zombiegeddon
-quote from an author, story books and fairy tales reappearing
-Richard Matheson was in the military and spent World War II as an infantry soldier
-Matheson's first short story, "Born of Man and Woman," appeared in the Magazine of Fantasy and Science Fiction in 1950. The tale of a monstrous child chained in its parents' cellar, it was told in the first person as the creature's diary
-I Am Legend is about a disease (Catacombs) that turns all but one man into blood-thirsty vampires
-could this one man be the icon, or perhaps vampires are returning
-"Full circle. A new terror born in death. A new superstition entering the unassailable fortress of forever. I Am Legend" was the last words spoken of the main character in the book
-I Am Legend, legendary truth
-I Am Legend, the storyteller was Mythos, but mostly referred to as legend at HHN XX
-will the new icon be legendary
-in the end of the film with Will Smith, people are seen entering a safe-haven or "the unassailable fortress of forever", and supposedly stay there forever
*Speculation