I will be brief on my write up but let him who has ear let him hear
Matthew 24:30
And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory.
What is the sign of the Son of man in heaven?
Christ made His prophecy about His second coming mainly on the book of Matthew 24 to the end so I am going to discuss basically from that chapter
In Matthew 24:30 "the sign of the Son of man in Heaven" should not be personally misinterpreted because before Christ was born the same sign of the Son of Man appeared as a Star in the cloud which was seen by the three wise men when He was born by a woman Mary,so Christ was prophesying in Matthew 24:30 that the same way He will come back again . He will come back again through the womb of a woman. So literally when He says the sign of the Son of man will appear in heaven and He will come in the clouds of heaven means He will born by a woman and all eyes will see Him .
Let me support the above Bible text from the book of Acts of the Apostles 1 :11 Which also said, Ye men of Galilee, why stand ye gazing up into heaven? this same Jesus, which is taken up from you into heaven, shall so come in like manner as ye have seen him go into heaven.
This for those Christian folks that are still gazing up at the sky for Christ to crash land. The Apostle were also looking at the heaven same way until they were told not to gaze up the sky by the angel which they never did so again.
To further support my point let open to the book of Revelation 12:5 And she brought forth a man child, who was to rule all nations with a rod of iron: and her child was caught up unto God, and to his throne.
Revelation reveals the future. The child reveals in that verse was no other person but Jesus Christ because beyond any contradiction we only have one iron rod Ruler that will rule all nation. She brought forth a male child means Christ is coming again through the womb of a woman. And verse 2 made more emphasis by saying " And she being with a child, travailing in birth, and pained to be delivered "

Let also look at preceeding verse which is Matthew 24:29
Immediately after the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken:
The symbol the sun be darkened and the moon shall not give his light has been used in the context of the old testament in Isaiah 13 vs 10-22(read).
It signifies a time of war and punishment of the world for their evil. In that verse Isaiah saw the war of Persian and medes against the Babylonians (the world super powers then). This I regarded as the first world war of the Bible era or the first generation after the world was created.
Christ said in book of Matthew 24:21
For then shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be.
According to history the greatest war recorded was the first world .google it;
World War I, also known as the First World War, the Great War, or the War to End All Wars, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918.
Wikipedia
Dates: 28 Jul 1914 – 11 Nov 1918
At least for now there has not been a great tribulation on earth as such until now. So let go by it until proven otherwise that these was the great tribulation Christ prophesied about before he will be born. To prove this was exactly the great tribulation on Matthew 24 He Christ said in the same Matthew 24:34 very I say unto you, this generation shall not pass, till all these things be fulfilled.
By all definition of generation( from same family set, 10-2000yrs) from my search, it has passed. So Christ second coming took place immediately after the first war 1.
Peace

Isaiah 63:1-6
1 Who is this that cometh from Edom, with dyed garments from Bozrah? this that is glorious in his apparel, travelling in the greatness of his strength? I that speak in righteousness, mighty to save.
2 Wherefore art thou red in thine apparel, and thy garments like him that treadeth in the winefat?
3 I have trodden the winepress alone; and of the people there was none with me: for I will tread them in mine anger, and trample them in my fury; and their blood shall be sprinkled upon my garments, and I will stain all my raiment.
4 For the day of vengeance is in mine heart, and the year of my redeemed is come.
5 And I looked, and there was none to help; and I wondered that there was none to uphold: therefore mine own arm brought salvation unto me; and my fury, it upheld me.
6 And I will tread down the people in mine anger, and make them drunk in my fury, and I will bring down their strength to the earth.

Let take a look at these quoted verse by my brother.
The verse 1 still talks about the second coming of Christ. Is Him alone that speaks in righteousness and mighty to save.
The book of Revelation 12:5 I have previously explained that Christ, the iron rod ruler will be born by a woman if you further read in revelation 19 vs 13 " And He was clothed with a VESTURE DIPPED IN BLOOD. And His name is called the word of God.
compare with Isaiah 63:2-3
2 Wherefore art thou RED in thine APPAREL, and thy GARMENTS like him that treadeth in the winefat?
3 I have trodden the winepress alone; and of the people there was none with me: for I will tread them in mine anger, and trample them in my fury; and their blood shall be sprinkled upon my garments, and I will stain all my raiment.
Both are referring to same personality, that is Christ reincarnation.
He is coming from the tribe of Edom this time not tribe of Jacob. Esau and Jacob signify two race which are the white and black race. So Christ has already come after the first war from the black race(Africa).
let go back again to Matthew 24:27
For as the lightning cometh out of the east, and shineth even unto the west; so shall also the coming of the Son of man be.
He Christ(Who is the Lightning)came first from the east, as Isreal was from the East so now expect Him to come from the West.
Jacob(Isreal)and Esau, West and East.
Peace