Disclaimer: Marvel, Fate/Stay Night and all related characters, concepts etc. are property of their respective owners, I own nothing, etc.

Age of Heroes

Prologue

Rin Tohsaka tapped her foot impatiently as the dial tone echoed in her ear.

C'mon, you stupid fake priest, the young Magus thought to herself, Pick up already!

The "fake priest" in question was, of course, Kirei Kotomine, supervisor of the Fifth Fuyuki Holy Grail War, as well as, for the last 10 years, Rin's guardian and mentor in arts both mystical and martial. Rin was hardly fond of Kirei, but she recognized that she wouldn't be half the Magus she was today if not for his teachings, and begrudgingly respected him because of it.

Finally, Rin heard a voice emerge from the telephone.

"Fuyuki Church," the voice spoke. The voice was deep, resonant, with an air of class and elegance. It had a warmth to it, but a dishonest, menacing quality as well, and it went a chill down Rin's spine. "Father Kirei Kotomine speaking. How may I help you?"

"I don't need the whole spiel, Kirei!" Rin snapped curtly. "I know it's you!"

"It's good to hear from you too, Rin," Kirei replied. Rin couldn't see the priest's face, but she knew for a fact that Kirei was wearing that annoyingly smug grin of his. "And just how is my favorite pupil this evening?"

"I didn't call for small talk, Kotomine," the irritated Rin responded. "I just wanted to let you know that I formed my contract with a Servant yesterday. So you can go ahead and register me as a Master, got it?"

Kirei remained silent for several seconds. Even over the phone, he made Rin want to tear her hair out. Ugh, hurry up and say something, dammit!

"Understood," Kirei finally answered. "Rejoice, Rin Tohsaka. You are now an official participant in the Holy Grail War." The priest's words carried a satisfied tone… a little too satisfied for Rin's liking.

What does he mean, 'rejoice?' Rin thought. Kotomine's always gotta be so damn melodramatic about everything…

"So, we done here?" Rin asked, in a hurry to be done with the conversation. "Cause it's been a long day, and I gotta get in bed-"

"One more thing, Rin," Kirei interrupted. Rin hated being interrupted. "There's something that I must tell you…"

"If it's about Father's will, you're a little late to the party," Rin nonchalantly declared. "I already deciphered that thing."

Kirei chuckled in response. "Well done, Rin. I've taught you well, haven't I? But in any case, that wasn't what I meant. We still need to discuss the matter of your travel plans."

The priest's meaning was lost on Rin. "Travel plans?" she repeated in bewilderment. "Where am I going? The Grail War shouldn't require leaving Fuyuki, should it?"

Kotomine chuckled once more. The laugh was a rich, throaty one, and the sound of it made Rin shiver with revulsion. "I don't believe I've told you yet, have I? The Fifth Holy Grail War will not be taking place in Fuyuki City, I'm afraid."

Rin's eyes went wide with shock. Her jaw was practically on the floor. After a few seconds of paralysis, Rin shouted indignantly at the priest. "What?! B-but that's impossible! Father told me the Grail War always takes place in Fuyuki! Why would it be any different this time?! Where even is it?!"

Rin could feel Kirei giving that self-satisfied smirk of his again.

"Why, New York City, of course."

Several months ago

Doctor Stephen Strange was deep in thought as he carefully poured a cup of tea. Not with his hands, of course. Those had been damaged for the better part of a decade. Rather, he manipulated the teapot using a basic levitation spell - one of the first he learned in his training under the Ancient One. As for why Earth's Sorcerer Supreme was so consumed in thought, that was a result of the strange markings that had recently appeared on the back the Doctor's right hand, and the implications presented by their presence. It was because of those same markings, in fact, that the recipient of the freshly made tea was sitting in Strange's study.

"Thank you, Doctor," Kirei Kotomine said, accepting the teacup from Strange's hand and taking a sip from it. "This is truly an honor - I'm sure there aren't many Magi in the world who can boast of being houseguests of the Sanctum Sanctorum."

"The honor is all mine, Father Kotomine," Doctor Strange merrily replied, taking a seat in his favorite chair. "It's all too rare a pleasure for me to entertain an official of the Holy Church."

As the office of Sorcerer Supreme is entirely distinct from the Mage's Association, Strange rarely crossed paths with the Church in his duties. While he commonly did battle with the sorts of beings the Church's Executors targeted - demons and vampires, among others - Strange's encounters with the Holy Church itself were few and far between. The closest connection the good Doctor ever had to the Church was through a rogue Executor named Isaiah Curwen, also known as the supervillain Silver Dagger. After a nasty run-in with the eldritch grimoire known as the Darkhold, Curwen declared war on all magic, believing it to be heresy against God. A belief that, unfortunately, was once shared by a majority of the Church. Personally, Stephen never understood the idea that mages were all heretics or devil-worshippers - after all, if not for the Sorcerer Supreme's efforts, Earth would have been conquered by the forces of Hell several times over by now.

"I would hope that any bad blood between the Church and the magical community would be a thing of a past by now," Kirei said. "Is this new age, there's hardly any point in such petty feuding, don't you agree?"

Kirei was right - the world had changed a great deal in the past decade. It was around eight years ago that the Fantastic Four first made their debut as costumed adventures, ushering in a new era of superhumans - the Age of Marvels, some were calling it. Before long, Tony Stark donned an armored suit as Iron Man, the Hulk and Thor came onto the scene, and Captain America was awoken from his frozen slumber. Within a year, the Avengers were formed, and they were hardly the last superheroes to appear. The X-Men, Daredevil, Ant-Man, the Heroes for Hire… and, of course, the hero who was perhaps Strange's closest friend in the costumed community, the amazing Spider-Man.

Magic and monsters were no longer a secret from the public, despite the best efforts of the Mage's Association, and as a result, most of the Association's time was now spent hunting down rogue Magi and recover long lost artifacts. Strange had little love for the Association - they were far too bureaucratic and elitist for his taste, more concerned with hoarding power for themselves than using their power for the good of others. However, there were some members of the Association who sought a reform of the organization's policies - most notably Lord El-Melloi II, head of Modern Magecraft Theories. Strange once had the pleasure of working with the young Lord when the two stopped a group of cultists in rural England from summoning Shuma-Gorath. That was in the past, however, and today, the present posed a more pressing concern to the Sorcerer Supreme.

"Indeed," Strange agreed. "Ideally, Magi and the Church should serve the same ends - protecting humanity from supernatural threats. That's my belief, at least. However, that's not why I invited you here."

Kirei gave a somber nod. "You wish to speak of the Holy Grail War, I assume?"

"Precisely." The Doctor removed his right glove, revealing the mystical markings adorning the back of his hand. The arcane tattoo consisted of three small diamond shapes, arranged in a triangular formation, enclosed by a circular outline divided into three segments mirroring the diamonds' structure.

The usually stoic Kirei was visibly surprised by the mark's presence, studying the design with rapt interest. "A Command Seal?!" Kirei exclaimed. The priest cleared his throat, and returned to his normal calm demeanor. "This is certainly a fascinating turn of events… the Sorcerer Supreme, chosen as a Master? Never in the history of the Holy Grail War has there been precedent for such an occurrence." Kirei practically chuckled the last sentence, clearly amused by the development.

"It certainly is unorthodox," Strange replied, examining the red markings. "The Sorcerers Supreme have never interfered in the Grail War, so I hardly expected to receive a Command Seal… especially since the Fifth Holy Grail War isn't due for another five decades."

"Ah yes… that," Kirei said - sighed, almost - clearly reluctant to speak of the matter. "I'm afraid the previous War ended in a rather… premature manner. The Grail itself was destroyed before its power could be depleted, and as such, it was able to regenerate the Mana it lost in a fraction of the usual time."

Doctor Strange nodded, stroking his chin. "I see," was his only response.

"Keep in mind, Doctor," Kirei continued, "Just because you have received a Command Seal doesn't necessarily mean you must participate in the War. If you choose not to summon a Heroic Spirit, there's plenty of potential Masters who would be able to take your place."

"Thank you, Father," the Sorcerer Supreme replied, "But actually, I fully intend to fight in the Grail War."

Kirei's eyes widened with surprise. For the second time in the conversation, the priest was caught off his guard. "Is that so? I mean no offense when I say this, Doctor, but what reason would you have to compete for the Grail? You are the Sorcerer Supreme, after all. The most powerful Magus in the world, and one of the only living wielders of True Magic. I doubt there's any wish the Grail could grant that you could not make reality with your own power. So, if you don't mind my asking, why do you wish to be a Master?"

Doctor Strange breathed a deep sigh, leaning back in his chair and steepling his fingers. "It is not the Grail itself that I desire, Father. Rather, I wish to participate in the War in order to keep the Grail out of the hands of those who would use it for ill. There are a great many Magi in this world who desire only power, without any concern for how many lives they destroy in the pursuit of said power. People like Baron Mordo, Kaluu, Kaecilius… Victor von Doom. People who, if given the power of the Holy Grail, would pose an immeasurable threat to humanity. As Sorcerer Supreme, it is my duty to keep the world safe from mystical threats, and as such, it is my intention to put a stop to any Masters who would use the Grail for personal gain. What better way to do that than as a Master myself?"

Kirei gave the Doctor an amused smirk. "I see. A noble goal indeed."

A contented smile appeared on Strange's face. "I'm glad you see it that way, Father Kotomine. Because I have another request. I want you to hold the Holy Grail War here, in New York City."

Of all the surprises Strange had given Kirei over the course of their conversation, that one was the most unexpected. Kirei barely kept himself from gasping out of shock.

"In New York, you say?" Kirei repeated, his eyes still wide. "This is certainly an unexpected request… after all, the Fuyuki Holy Grail War has always taken place, well, in Fuyuki."

Strange's expression became stern, his tone deadly serious. "As I said, I am Earth's Sorcerer Supreme. It is my responsibility to keep humanity - all of humanity - safe from dangers of a magical nature. Therefore, I think it would be best to conduct the War on a battlefield where collateral damage can be kept at a minimum."

Kirei raised an eyebrow in confusion. "I fail to see how holding the War in the most heavily populated city in America would do anything to reduce collateral damage, Doctor."

The Sorcerer Supreme nodded in response. "Indeed, New York is exponentially larger than Fuyuki City. However, it's also the superhuman capital of the world. The Avengers make their home in New York, as do the Fantastic Four, and more costumed vigilantes than anyone can count. Not to mention the Triskelion, SHIELD's world headquarters, floating in the East River. No city in the world is better equipped for dealing with supernatural dangers than New York. It's been eight years since the Age of Marvels began, and since then, the fantastic has become mundane for the people of this city. Whether it's Heroic Spirits or just plain heroes doing the fighting, this city can take it.

"Now, don't misunderstand, Father," Strange continued, "I don't intend for the superhuman community to meddle in the Grail War. The War will be kept strictly between Masters and Servants, no outside interference. I only wish for the Avengers and SHIELD to help keep casualties at a minimum, to clean up the War's mess, so to speak, just as the Church has in the past. Evacuation of civilians, damage control, et cetera. I trust those terms will be reasonable?"

Kirei directed a grim, almost contemptful look towards the Doctor. "And what if the Church and the Association don't find your terms reasonable?"

Strange gave a cheeky, audacious grin in response. "I'm the Sorcerer Supreme. I'm sure they will."

Kirei was silent for a moment, as if contemplating Strange's words. Then, he let out a low chuckle, which soon grew into a grand belly laugh that echoed throughout the Sanctum Sanctorum. The sound was equal parts jovial and blood-curdling. While Strange had no reason to see the priest as anything but trustworthy, a part of him became fearful of Kotomine at the sound of his mighty cackling.

After his laughter died down, Kirei fell silent once more for a few seconds before replying. "Indeed, Doctor!" Kirei concurred, his tone much more expressive and genial than before. "I will see what I can do."

Kotomine extended his hand to Strange, who shook it in kind. "It's been a pleasure meeting you, Sorcerer Supreme. I'm sure this Holy Grail War will be one to remember."

Doctor Stephen Strange was deep in thought as he shook the priest's hand. He wondered what Masters and Servants he would face when he fought in the Grail War. He wondered what kind of Servant he would end up summoning. He wondered if Kotomine could be trusted. But most of all, he wondered if he was truly doing the right thing.