Note this is a prologue to an idea I've been thinking of for some time. Note this is a crossover. But before we begin, the route that Shirou takes in this is mix of all three routes.

Prologue

The Age of the Gods, it was a time where creatures of myths and legends ruled the Earth, a time when humanity is nothing more but a minority to the Phantasmal Species. During this era the will of Gaia, the powers of the inhabitants and the souls that exist on this blue world are completely intertwined together.

But like all things there is a beginning and there is an end. Two thousand years ago the decline of the Age of Gods began, Species of great majesty and power began to disappear from the world, Divine Spirits and the so called Gods followed. And as these forces of nature fade from the lands, humanity began to drift away from their origin and Alaya. And in time would outlive the life of Gaia.

The powers of Magecraft began to decline as practitioners scramble to preserve those that they can.

Soon the Age of the Gods faded from humanity's history. The Gods and the creatures that once live among us had by and large faded to nothing more but legends and figments of imagination of the now mundane world of humanity.

Mages, humans who practice the concept of Thaumaturgy and the remnants of the species of old, formed into small communities and organizations, isolating themselves from the rest of humanity.

But why did the Age of the Gods end? Even today, after centuries since the events that herald the collapse, the causes of the decline continue to remain a mystery. Theories and other speculations tried to gave concrete answers for its demise. Yet no one ever came close to the answer.

The few that knew the truth however, discovered something far older and more powerful than anything on this planet or this universe.

Deities that exist outside of our fabric of reality, unrecognizable forces that bends the very boundaries of both the physical and spiritual essence of our universe on a whim, even the most powerful of Transcendent Kinds is insignificant to them.

I am one of the few that knew the truth. The end of the era of the Gods was not due to separation of humanity from the Roots, but from a frenzy of blood and destruction, a massive genocidal slaughter that stems from the cosmic horror that exist beyond our reality.

My name is Kischur Zelretch Schweinorg, Master of the Second Magic "Kaleidoscope," and I have seen the horrors that exist beyond the void of space. Even in deathly slumber their influence continues permeate minds of many throughout the different parallel universes that I've traveled through. If awakened it would mean the either the complete destruction or the perversion of reality as we know it.

Yet even as humanity and the rest of the universe unknowingly face a force that could snuff out our existence at any given time, a ray of hope stood in defiance against the greatest threat of all existence-

OK, before I continue, that person is totally not me. I may be the most powerful Magus to boot…and now and then did some really awesome things here and there, i.e. kicking Brunestud of the Crimson Moon's ass, supervised the creation of the Holy Grail War with my students, etc, etc….. Getting laid in probably over halve of the dimensions that I traveled to. Ah good times.

Anyway the man I speak of is probably one of, if not the most important man in history. It was through him, that Gaia and our Universe for that matter is still here.

He has fought against these deities since the Dark Ages, and saved countless lives and preserved the existence of many races that would have been extinguished and has risen in power far beyond that of this planet and in the end sacrificed his soul for the preservation of all sentient life.

But even with his sacrifice the danger has not pass. While these Deities "Outer Gods" as we call them remain sealed from reality there servants continue to find ways to unleash their Gods and bring destruction.

Those that remain that know the truth will continue the fight. Until the time of his successors, his Children take on the mantle.

Till then I have a promise to keep, when I first discovered existence of the "Outer Gods" my curiosity nearly got myself killed, apparently the immortality of a True Ancestor means nothing compare to Cosmicism.

I would've died if it were not for him. For that I intend to return the favor.

With his Sacrifice, the remaining obstacle that truly poses a threat to them is his children.

But first, I think you all are probably itching to know just who I am talking about just what kind of a person this is. To face down beings that even the great Zelretch, the Wizard Marshall could not defeat.

Unfortunately, I'm not going to tell you his name, I believe the people who have the right to know his name first are his family his parents his father and mothers. Yes you heard me mothers with a S.

But what I will tell you is this; he is born from the blood of Kings, Heroes and Magus's. He is the Lord of Dragons, master of the Fourth Magic, the first to truly defy the Outer Gods. He is the offspring of the King of Knights, the King of Swords and the House of Tohsaka.

And this is his Legacy.

End Prologue