'Mighty Angel' in the Bible

And I saw a mighty angel proclaim with a loud voice, Who is worthy to open the book and to break its seven seals?

AND I saw another mighty angel come down from heaven, clothed with a cloud, and an iris was about his head, and his face was like the sun, and his feet like pillars of fire,

And a mighty angel took up a stone like a great millstone, and cast it into the sea, saying, Thus with violence shall Babylon the great city be cast down, and shall be found no more.