An impossible crossover across worlds. In an alternate universe, to avoid the cringes of poorly told tales. A promise for a tale never told before. FMA Brotherhood x RWBY x Generator-Rex x LOA. The year is 1983, when the world fell to the despair of the deities that would alter the fabric of existence, give rise to a broken realm where mankind is subject to challenges the world before then never faced. No pairings yet, prepare to be blown away.

Prologue

The year is 1983.

The man wiped the stone with the sleeve of his tattered lab-coat. Once white and warm, was now a grimy, earthen color and the threads of fabric worn into little more than fine, ready-to-tear clothing – at least where there were no gaping holes.

One mad woman had done it. One mad woman had finally stirred the wrath of the gods, and existence, as it was known, was being torn to shreds. His hand shook and the stone slate he held trembled with them.

Wan Fan was a simple man.

Well… perhaps "simple" did not really describe a man of science with an insatiable desire for knowledge and a drive to unearth the world's greatest mysteries. His discoveries had broken the barriers of established scientific laws and brought the dawn of a new age to the forefront of tomorrow.

Except, he knew now, that tomorrow would never come. With this knowledge, he realized that at that moment, all he could be was a simple man. A simple, desperate man.

Even as fire and hail rained down on the rest of the world, Wan Fan had all of his will propelling him to his final acts before he and all of mankind would perish. But all that drive was not to preserve his work, nor his creations. None of that mattered, he knew. It never would.

He was preserving a message for the future.

Somehow, in what seemed to be the final dying moments of humanity, he knew that this was not the end. For him and everyone who was still breathing, yes. Tomorrow would never come for them, but man would have a chance to thrive again. Tomorrow belonged to them.

The year is 1983.

That was the only message in his head that the occupants of the otherworldly realm had given him. He chuckled dryly as he staggered around the re-enforced basement of his 44 story-laboratory, scatterbrained in his search to find something that would survive the chaos. The bunker-basement was the only thing that stood between him and the end as the world knew it, and even then it was fast giving way to the cruel elements of destruction. The ground shook below him as he desperately searched for something that would preserve the easily perishable stone tablet in his hand, where he had burned the prophetic information with a blow torch. He had to preserve the message that had been given to him by his newly recognized deities. Never in his forty years did he believe in the concepts of gods, yet he became their chosen oracle for a future that seemed non-existent at the brink of an apocalypse – the irony of it all was amusing. He had no idea what the message meant, but at the moment the revelation came to him he had realized that it didn't matter. The message was not for anyone who was on the surface of the earth at that moment. They had no concern for it, only their end.

Their end brought about by a mad woman.

The ground below him started to tear open, and the scientist had the good sense to dive to the side as the floor broke itself apart. Wan Fan swore loudly and cursed the beings who tasked him with this. As one who knew there was no escaping the end, all he wanted to do was lie down and wait to die. But the burden of ensuring this message was preserved filled him with anxiety. Nothing in his bunker would last through long enough for life to restart before decomposing – assuming it somehow survived the ensuing chaos; knowing this made the poor scientist restless.

'This should not matter to me! I have no business with what the future holds when my own demise is so eminent! But yet you have made me restless and unable to accept death until I ensure this message will reach the future!' he spat on the ground as it shook and broke apart, struggling to find a relatively safe footing away from the walls that started to tear apart also. Low rumblings of the chaos outside quickly rose in volumes once the soundproof barrier was pierced, and between the screams of people and the sound of thunder as giant hail struck against the ground, the man's bones chilled. He cursed again. 'If I was a layman I would be quite content with letting this stone stay on the ground and accept death, believing it would stand the test of time. But I'm a man of science! I know there's no way your message will survive through this disaster or through time, not on anything in this bloody room! Let me survive as the last one to preserve this bloody message, or you better damn well make me an alchemist who will be able to turn this thing into something durable enough damn you!'

His body felt as though he was consumed by fire even before his final words – of a morbid sarcastic humor mind you – left his mouth and he roared in agony. The ceiling began to fall apart as the building crumbled under the weight of natural disasters, and he shook violently, fearing he had angered the deities he had just scorned. His eyes felt as though they were burning, glowing with blinding white light.

The year is 1983.

He paused. Then added something beneath it.

The witch is Salem.

The Advent.

That was what history called it. That point in time's past beyond which no historian or scientist could provide answers, the null and void, the forgotten, the erased, the dawn of being, the beginning. The names were endless for that point in the timeline of their existence. Man was born from the Advent, life to walk the earth that was birthed before him. He was born into a struggle to survive with the creatures that roamed the lands and the unharnessed powers that pulsed the ground. And for a time, it seemed as though he could not compete and would fall into extinction as quickly as they came into existence. But then the power of the ground was taken and made their own, mysterious crystals of great capabilities; man triumphed over the creatures of darkness and thrived.

In the wake of their victory, mankind advanced in strength and knowledge. They dug deeper and deeper with their minds and tools to uncover the fossils that would reveal how they came to be and the formulas that generated their being. And fossils they did find, formulas they did solve, but the further they went, the narrower the directions their findings unearthed became, leading to the singularity, the void, the Advent.

No school of study could provide the answers that would explain the Advent. It was simply what it is, that point from which being came to be, and as man would start to walk the face of the earth and build their civilizations and tools, the scholars would record it as such: uncontested, irrefutable fact.

Man continued to grow, building civilization and bringing life to the earth-born from the Advent. The power of the ground that won man's established place in existence gave rise to great things. The name for this resource varied as mankind expanded and diversified and how the resource perceived varied along with them. Dust, element, the elixir of life, philosopher's stone, the essence of the spirit realm, the aura of the earth, the names were as unique as the capabilities that came with it. Though it was unlikely to finish anytime soon, it was exhaustible, and attempts to recreate it have always left… some things to be left desired.

The null and void, the forgotten, the erased, the dawn of being, the beginning, they all pointed down to one thing in history – the Advent was the dawn of all things. 'Twas known fact in the world today.

And the gods help you, if you contested this law of Genesis.