This Angel with great authority is Christ. As He comes down out of heaven, the earth is illumined with His glory. In Rev. 10:1 Christ is still clothed with a cloud, and in Rev. 14:14 He is sitting on the cloud; whereas here His glory shines over the earth, indicating that His coming back to earth is nearer at hand than the coming mentioned in 10:1 and 14:14. He will come out of heaven, first in the cloud secretly, then on the cloud openly; eventually, He will shine over the earth to destroy Babylon the Great, the city of Rome, with His great authority.