"..make war with the rest of her offspring..."
Further enraged by his second failure, Satan now sets forth to make war with those saints who remain in the land after the faithful of Jerusalem escape safely into the wildreness. Those remaining are the ones mentioned in Matthew 24:15 which flee into the mountains when they see the Abomination of Desolation stand in the Holy Place. These too are likely the ones of Israel chosen to bury the hordes of Gog in the Valley of Hamon-Gog (Ezekiel 38:12). They are distinguished from their mother (the woman) who fled into the wilderness, by the fact that she fled (Chapter 12:6) before the revelation of the Antichrist (Chapter 13:1,5). The remnant of her seed will flee into the mountains when they see the abomination of desolation set up, at his revelation. It may well be that these are the ones which many believe will flee the the ancient city of Petra in the desert south of Jerusalem. Scripture states that those which live in Judea should not enter into Jerusalem, but should flee into the mountains when they see the "abomination of desolation" stand in the Holy Place.
Having two dismal failures to his credit, now prompts Satan to initiate a new plan whereby he transfers his power and authority to someone who appears to be very trustworthy and capable in his eyes; and one who shares his great wrath, as well: the Beast of Chapter 13.