Revelation 16:14
For they are spirits of demons, which perform [supernatural] signs. These spirits go out to the kings of the whole world to assemble them for battle on the great day of Almighty God.
Revelation 16:16
So, the [demonic] spirits assembled the kings together at the place which is called "Armageddon" in Hebrew. [Note: "Armageddon" means "mountain of Megiddo" and was a site in northwestern Palestine where several decisive battles had been fought centuries earlier. See Judges 4,5,7].
Revelation 20:8
and he will [again] go out to deceive the nations which are [located] throughout the whole world --- Gog and Magog. [Note: Based on Eze. 35-40, it appears that these names are used here figuratively for all the forces of wickedness which are enemies of God]. Satan will assemble them together for battle, and they will be as numberless as the sand on the seashore.