Revelation 10:1 And I saw another mighty angel come down from heaven, clothed with a cloud: and a rainbow was upon his head, and his face was as it were the sun, and his feet as pillars of fire: 2 And he had in his hand a little book open: and he set his right foot upon the sea, and his left foot on the earth, 3 And cried with a loud voice, as when a lion roareth: and when he had cried, seven thunders uttered their voices.
Some think the “mighty angel” is “Christ”, and some think it is “another mighty angel”. The rainbow is like the rainbow in Genesis 9:8 where God made a promise to Noah. The pillars of fire is like the description of Christ in Revelation chapter one. The lion is like Chist as the Lion of the tribe of Judah in Revelation 5:5.