Revelation 16:12
The sixth angel poured his bowl into that great river, the Euphrates; and its stream was dried up in order to clear the way for the kings who are to come from the east.
Revelation 9:14
It said to the sixth angel--the angel who had the trumpet, "Set at liberty the four angels who are prisoners near the great river Euphrates."
Revelation 7:2
And I saw another angel coming from the east and carrying a seal belonging to the ever-living God. He called in a loud voice to the four angels whose work it was to injure the earth and the sea.
Revelation 11:14
The second Woe is past; the third Woe will soon be here.
Revelation 17:15
He also said to me, "The waters which you have seen, on which the Harlot sits, are peoples and multitudes, nations and languages.