Heavenly War

"It is better to reign in Hell than serve in Heaven!"

- Lucifer to his generals

Heavenly War, also known as the War in Heaven, is the grand conflict between the rebellious Angels under Lucifer and the loyal Angels under Michael.

It began after the first humans were created who made Lucifer believe that he should be the new King of Heaven and rebel in the process.

Overview
The Book of Revelation describes a war in heaven between angels led by the Archangel Michael against those led by "the dragon", identified as the devil or Satan, who will be defeated and thrown down to the earth. Revelation's war in heaven is related to the idea of fallen angels, and possible parallels have been proposed in the Hebrew Bible and the Dead Sea Scrolls.

Summary
The Heavenly War is the first conflict in existence, began shortly after the first seven days when Cosmos was created by God. It stemmed from Lucifer himself, who became angered and insulted when God proclaimed humanity was Their greatest creation and commanded the Angels to bow before them. He then rallied his followers across Heaven and planned an attack upon the Heavenly Council to take over the Cosmos and rebuilt it based on their own image.

In the end, Lucifer and his forces were defeated and banished into the deepest realms within the Outside, which will eventually be known as the Underworld, by Michael and the Heavenly Host. There, the Angels who followed Lucifer became the Demons while the generals under Lucifer's became Archdemons.

Prelude
When God created humanity, They deemed them as Their greatest creations and ordered all the Angels to bow down to them, which they all did except for one Angel, being the Celestial Prince Lucifer (then known as Helel). As Lucifer was said to be the most beautiful and majesty of all heavenly beings, he was prideful as he knew there was not another that could rival him in beauty in existence.

When Lucifer refused, his head grew twisted with pride and paranoia, making him thought that this wasn't an order from God but rather from his own siblings, especially Michael, and started to think that they were now all flawed, both his siblings and even their Creator Themself, and thus, does not deserve to be the rightful ruler of all existence. He then believed that he himself should be the new Supreme God and began to plot to try and take God's throne for himself to rule over Creation.

He then rallied, persuaded, seduced, and manipulated one-third of all the other Angels into swearing an eternal allegiance to him - though his efforts might not be worth it as all Angels, barring his own siblings, would gladly swear it based on their adoration and admiration for him alone - and to go to war against God and the Heavenly Host.

History
According to many sources, the first strike was made when Lucifer infiltrated the Garden of Eden and seduced Lilith, corrupting her immortal soul and turned her into the first Devil, which led to her banishment from the Garden by the Heavenly Council.

Lucifer then led his armies into Heaven to destroy the Heavenly Host and all those who dared to oppose him, and to storm God's throne room. However, the Celestial Prince Michael had led the Host to make a counter attack and warred with Lucifer and his armies. The war seemed to be endless, with Heaven being stained by ichor and heavenly fire of the slain Angels of both sides, as the heavenly beings fell from the utmost high with their wings torned apart, along with others who fell from the Heavenly Council's growing paranoia.

While the other Angels fought each other, Lucifer was able to enter the Empyrean as he was planning to face God on his own. Instead, Michael was in front of him with the Elder Seraphim around him. Michael had gone to the final hallway while the entire guard had then rushed to Lucifer who was able to defeat them all with barely any effort.

Lucifer then went after Michael and faced each other face-to-face. Michael pleaded for Lucifer to stop this rebellion as countless Angels in both sides had perished in the conflict but realized that it was futile as Lucifer was not going to stop in his path, ths forcing him to go against his own twin brother. And while Michael was a formidable warrior, even he couldn't compare to the Morningstar as he was swiftly defeated and Lucifer stepped into the throne room of God.

It's still a mystery as to what happened within the throne room, as no one was able to enter it during this brief period, though after what Michael had deemed "hours", Lucifer left the room with "tears of blood staining his flawless beauty" after receiving a "revelation" from God. Taking advantage of this, Michael made a sneak attack which caught the Morningstar in surprise and threw him down from the Seventh Heaven.

Lucifer, humiliated and torn by what God had revealed to him, had, in his unyielding rage, created the Dragon Gods from his sheer anjeer and ordered them to rampage through the heavens, before rushing back to Heaven to crush any Angel who stood in his way.

The events after that became murkier and murkier to theologists and historians as documents about this brief period are little to none. All that is known is that after a long and difficult battle, in which the casualties ranking in googolplexes, Lucifer and his forces were finally defeated and cast down into the deepest and darkest region of the Ein Sof, and away from Heaven.

Lucifer, in particular, was sealed into a Cage created by the Celestial Princes in the furthest place within the infernal domain where his forces were banished to, furthest from the light and glory of Heaven.

Conclusion
After losing the war, Lucifer's forces were banished and their descent was said to be likened to those of an endless barrage of falling stars that shifted the Axis Mundi. They were then corrupted by sin and their own powers and transformed into a new race of infernal beings: Demons, with the generals personally serving beneath Lucifer became the highest and most powerful Demons called the Archdemons.

Despite being sealed within the Cage, Lucifer was still able to spiritually walk upon the worlds beyond with little restrictions, as his grace was greater than any other Celestial Prince. He then used his nigh-omnipotent powers to reshape the region where he and his followers were banished into a mighty realm that is in no way inferior to Heaven's might, which he named Sheol.

Lucifer crowned himself Ha-Satan, meaning the "Great Opposer" in the Adamic language, and the Supreme God of the Underworld. He then appointed seven of his most powerful generals as the Emperors of Hell and formed the government of the Underworld known as the Stygian Council.

The Demons themselves would then divide authority among themselves, forming numerous rankings of Kings, Dukes, Princes, Marquises, Earls, and Presidents. Lilith, who was banished from the Garden of Eden, was taken in as Lucifer's adopted daughter and married to the Emperor of Hell Asmodeus, and from their union, the Devil-race was born, who served as the Demons' servants, soldiers, and slaves. Numerous dark and demonic creatures were also created as a mimicry of the animals created by God that reside in the Garden.

The Dragon Gods, who were merely creations born from Lucifer's spontaneous anger, were spared from death by God before the Elder Seraphim could kill them. They then sent them to live Tellus Mahte among other beasts and animals, and later on, among other primordial humans.

Quotes
"The mind is its own place, and in itself can make a heaven of hell, a hell of heaven..."

- Lucifer "And war broke out in heaven: Michael and his angels battled with the dragon, and the dragon and its angels battled but it did not prevail, neither was a place found for them any longer in heaven. So down the great dragon was hurled, the original serpent, the one called Devil and Satan, who is misleading the entire inhabited earth; he was hurled down to the earth, and his angels were hurled down with him."

- Revelation 12:7 - 9

Trivia

 * It's rumored that the reason Samael tempted Adam and Eve in the form of a serpent was because Lucifer had tempted Lilith in the form of a Dragon.
 * It's said to be the same reason why the Heavenly Council is paranoid toward the Dragon-kind.
 * Many places in Heaven are still stained gold with the ichor and heavenly fire of the Angels slain in the Heavenly War.