Revelation 5:2
And I saw a strong angel proclaiming with a loud voice, "Who is worthy to open the book, and to loose its seals."
Revelation 5:5
But one of the Elders said to me. "Do not weep! Behold, the Lion of the tribe of Judah, the Root of David, has conquered, and so can open the book with its seven seals."
Revelation 18:21
Then a mighty angel lifted a boulder like a great millstone, and hurled it into the sea, saying, "So shall Babylon, the great city, be overthrown with a mighty fall, And shall be found no more at all.
Revelation 10:1
And I saw another mighty angel coming down out of heaven, clad with a cloud; and a rainbow was upon his head, and his face was like the sun, and his feet like pillars of fire.