Clouds always make me think of heaven. Maybe it is because when God ascended into heaven He was hidden by a cloud. (Acts 1:9). Also, when God appeared to the ancient Israelites, He was often hidden by a cloud. (e.g. Exodus 13:21).
Recently in recognition of the Archangel Michael’s service to our Lord, the Church celebrated Michaelmas. Michael fought the dragon in heaven:
Now war arose in heaven, Michael and his angels fighting against the dragon. And the dragon and his angels fought back, but he was defeated, and there was no longer any place for them in heaven. And the great dragon was thrown down, that ancient serpent, who is called the devil and Satan, the deceiver of the whole world—he was thrown down to the earth, and his angels were thrown down with him.
— Revelation 12:7-9, ESV.
The scenes from The Lord of the Rings: The Fellowship of the Ring & The Two Towers where Gandalf stands against and fights the Balrog are a fun artistic symbol of this battle. I quite enjoy this quote from Gandalf: “From the lowest dungeon to the highest peak I fought with the Balrog of Morgoth… Until at last I threw down my enemy and smote his ruin upon the mountain side…”
— Gandalf; The Lord of the Rings: The Two Towers
And I heard a loud voice in heaven, saying, “Now the salvation and the power and the kingdom of our God and the authority of his Christ have come, for the accuser of our brothers has been thrown down, who accuses them day and night before our God. And they have conquered him by the blood of the Lamb and by the word of their testimony, for they loved not their lives even unto death. Therefore, rejoice, O heavens and you who dwell in them! But woe to you, O earth and sea, for the devil has come down to you in great wrath, because he knows that his time is short!”
— Revelation 12:10-12, ESV.
The picture above makes me think of the Last Day when Christ will return with all the armies of heaven marching in order. The time is indeed short.