Ok so “true” Christianity went underground when Constantine converted in 313AD? I get that right? LOL…

True Christianity was underground from the start. The persecution was real and the Roman Empire slaughtered the early Christians.

The Bible you follow, assembled & organized by council of Niscia is the Bible you follow, even though it was assembled Holy Roman Catholic Church? The “evil” church by your accounts, right? Ok… See your circular logic?

Hate to break it to you, but the Bible was around long before Constantine organized the First Council of Nicaea and ensured the Book of Enoch was removed from it, as well as ensuring the switch to a solar calendar instead of the lunar calendar so that Easter would fall on the vernal equinox.

Roman Catholicism is veiled sun worship after all, the pagan religion of the Romans with Christian archetypes and saints replacing the traditions and the gods and goddesses of old.

Ok, moving on, so then Christianity went underground after “evil Constantine & Pagan Rome” converted to Christianity (but didn’t, according to you) & suddenly sprung up after Luther’s revolt in the 14th century & “the good guys won” and good Christianity, Christianity 3.0. Are the good guys?

The Eastern Orthodox church fled as far as Russia to escape persecution of both the Roman Catholics and the Muslims. This is what preserved the Holy Bible in the original Koine Greek and Hebrew.

Keep pretending Protestantism didn't lead to the emergence of a middle class along with proper hygienic practices (thanks to the cleanliness laws found in the Old Testament), etc. and that the feudal system with a bunch of illiterate serfs was a good thing.

Protestantism ultimately failed because the leaders didn't cut all the strings to Rome. Their biggest mistake was clinging on to the man-made traditions and all of the fighting and confusion between different Protestant denominations came from disagreements about those things.

And by the way, the Dark Ages were prophesied by Yeshua in the Book of Revelation.

Revelation 12:1-6

1 And there appeared a great wonder in heaven; a woman clothed with the sun, and the moon under her feet, and upon her head a crown of twelve stars:

2 And she being with child cried, travailing in birth, and pained to be delivered.

3 And there appeared another wonder in heaven; and behold a great red dragon, having seven heads and ten horns, and seven crowns upon his heads.

4 And his tail drew the third part of the stars of heaven, and did cast them to the earth: and the dragon stood before the woman which was ready to be delivered, for to devour her child as soon as it was born.

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.

6 And the woman fled into the wilderness, where she hath a place prepared of God, that they should feed her there a thousand two hundred and threescore days.

In prophecy, a woman is a church, and a day is likened to a year. In verse 6, this is a 1260 year prophecy.

The ancient Roman empire AKA the dragon was divided into 10 kingdoms after the barbarians sacked Rome.

The dragon had 10 horns but only 7 heads and 7 crowns.

Why do you suppose that is? 3 of the horns or kingdoms were completely wiped out by Justinian before the Bishop of Rome took their place on the head of the dragon.

Emperor Justinian I was a famous Byzantine (Eastern Roman) Emperor who captured much of Rome from the barbarians who sacked the Western empire and instituted new legal codes in the former Roman capitol after doing so.

According to the Catholic Encylopedia article on from the section Military triumphs-

Belisarius in 536 took Rhegium and Naples, entered Rome in triumph, seized Ravenna, sustained a siege in Rome till 538, when the Goths retired.

https://www.newadvent.org/cathen/08578b.htm

Archived link - https://archive.ph/OulsZ

According to the same article, in the section entitled Legal work, Emperor Justinian I codified the laws of the Byzantine Empire, basing them on ancient Roman laws.

The article doesn't say this but this was known as the Codex Justinianus.

An English translation can be found here on archive.org-

https://archive.org/details/fred-h.-blume-bruce-w.-frier-the-codex-of-justinian-a-new-annotated-translation-

On page 32 of 3176, we find the following was part of the Codex-

The Conqueror JUSTINIAN, Pious, Fortunate, Renowned, Triumphant, Ever Augustus, to the Most Holy John, Archbishop and Patriarch of the Generous City of Rome. 8. Rendering honor to the Apostolic See and to Your Holiness, which has always been and remains Our wish, as it ought to be, and honoring Your Blessedness as a father, We hasten to bring to the notice of Your Holiness everything concerning the status of the churches, since We have always greatly desired to preserve the unity of Your Apostolic See and to maintain the status of the Holy Churches of God, as it has heretofore prevailed and continues undisturbed without the interference of anything to the contrary. 9. We have therefore hastened to make all priests of the whole Orient - subject to the See of Your Holiness and to unite them with it. 10. And We therefore deemed it necessary to bring to the notice of Your Holiness what action presently has been taken here, although it is clear and unquestioned and has ever been resolutely observed and preached by all priests in accord with the teaching of Your Apostolic See.

We permit no action to be taken concerning the status of the churches, however clear and unquestioned it may be, but that it should come to the notice of Your Holiness, because You are the head of all holy churches. For in all ways, as stated, We strive to increase the honor and authority of Your See.

So Justinian recognizes the Bishop of Rome as the ruler of the Holy Churches of God in 534 AD. This law doesn't take effect in Rome until 538 AD, when the siege of Rome ended, as recorded in the Catholic Encylopedia.

What happened 1260 years later as prophesied in Revelation?

According to the Catholic Encylopedia article on Pope Gregory XVI-

In 1798 took place the scandalous abduction of Pius VI by General Berthier, at Napoleon's orders, and in the following year the death of the pope in exile at Valence.

https://www.newadvent.org/cathen/07006a.htm

Archived link - https://archive.ph/7WEl

The Pope was imprisoned and the Roman Catholic Church did not take power again until recognized by Adolf Hitler and the Nazis at the signing of the Lateran Treaty of 1929.