Revelation 16:12
The sixth angel poured out his bowl on the great river Euphrates, and its water was dried up, to prepare the way for the kings from the East.
Revelation 9:14
saying to the sixth angel who had the trumpet, "Release the four angels who are bound at the great river Euphrates."
Revelation 7:2
Then I saw another angel ascend from the rising of the sun, having the seal of the living God, and he called out with a loud voice to the four angels who had been given power to harm the earth and sea,
Revelation 11:14
The second woe has passed; behold, the third woe is coming soon.
Revelation 17:15
And he said to me, "The waters you saw where the harlot sits, are peoples and multitudes and nations and tongues.