'Mighty Angel' in the Bible

And I saw a mighty angel announcing in a loud voice, "Who deserves to open the book and break its seals?"

Then I saw another mighty angel coming down from heaven. He was clothed in a cloud, with a rainbow over his head; his face was like the sun, his legs were like pillars of fire,

Then a mighty angel picked up a stone like a huge millstone and hurled it into the sea, saying: "With violence like this, Babylon the great city will be hurled to ruin, and it will never be found again.