Prologue

As the final notes of Kousei's part for Saint Saen's Introduction and Rondo Capriccioso concluded, Kousei breathed a massive sigh of relief as the last note faded away. The diminuendo was comforting…the performance was over! He looked over at Kaori. Surely she must be enraged at him for his hideous accompaniment that had thrown her off, right?!

But no…she just stood there, with her back turned to him, basking in the momentary blessed silence that filled Towa Hall. Then, the audience erupted into thunderous applause and cheering for the duet. Kousei smiled; he'd done it! THEY had done it! They'd given a grand performance despite the lack of rehearsal! Kousei's breathing slowed as he took in the audience's shouts of appreciation. Then, he felt his face grow warm as he blushed with admiration looking at Kaori. Her long, beautiful blond hair swayed ever so slightly, and her hands which gripped her bow and violin shook from the sheer joy of their victory. Kousei figured now was as good a time as ever and called out her name.

But then, the moment the "i" of her name departed his tongue, something changed. The audience's applause abruptly ceased, and Kaori's arms dropped to her sides. The overhead lights grew dark, and Kousei gulped. What was happening?! Had saying her name in front of the crowd embarrassed her to the point where it tainted their accomplishment?

As Kousei continued to observe, frozen by fear, some of Kaori's elegant blonde hair suddenly began to fade into a ghostly pale-yellow, grow somewhat shorter, and even…fall off! Her skin changed from a healthy, vibrant tan to bright white like that of a leper, and when she turned to face her accompanist, the gorgeous, sweet face he'd fallen in love with had been replaced by an eyeless, sneering skeleton head.

Kousei screamed.

He tried to get up from piano bench and run for his life, but in that moment his knees turned to jelly, and his feet were stuck to the floor! His eyes were locked with Kaori's empty sockets, but in his peripheral vision he saw that the audience members were beginning to suffer the same fate! Doomsday sirens blared and rose to an impenetrable din as Kousei quaked with terror on the music bench.

"No, no, no!" he thought in horror. "Why is this happening?!"

Just when he thought it couldn't get any worse, Kaori…began walking over to him! Her skin had completely disappeared by now; all that was left were thin, scrawny bones that could no longer hold her precious violin and bow. Her skeleton body was only clothed in a frail, white dress. But clearly, her arms still had some strength as they seized the helpless Kousei and gripped him with feral rage.

Kousei gasped, and struggled to break free of the horrid, bony arms. But then, he felt another pair of arms grab him…then another...and another…and another! Turning around, he saw that five more of Kaori's nightmarish skeleton form had suddenly appeared and surrounded him! He jerked back and forth with all his might, but the ghouls held him firmly, preventing him from escaping this hellish concert hall.

"You couldn't save me," the Kaori ghoul on his left hissed. A shiver ran up Kousei's spine.

"You couldn't save me," the one on the right repeated.

"You couldn't save me!" the one behind wailed.

"You couldn't save me!"

"You couldn't save me!"

"YOU COULDN'T SAVE ME!"

As the six anguished and vengeful Kaori ghouls held him down, Kousei suddenly felt something wrapping around his ankles! He looked down; deadly black vines were grabbing him from below! A dark, bubbling violet liquid formed underneath the piano bench, and Kousei saw his shoes disappear as the six monsters aided the vines in dragging him down to the abyss.

Kousei looked at the Kaori ghoul directly in front of him, sobbing in terror. He begged for mercy, for forgiveness. For one last chance to play with her before he faced his punishment for his weakness. But the six Kaori ghouls just cackled.

"Oh Kousei," the one behind him taunted. "There is no way you can truly atone for this now, is there?"

"AAAAAAAAAAAAAAAAAAAAAAAHHHH!"

Kousei sat bolt upright in the fallout shelter, his body drenched in sweat and his black hair frizzled. He fumbled for his glasses, felt them in their usual spot to the right of his head, and put them on. It took quite a while for his breathing to slow; this was the seventh time this nightmare had happened!

As he regained his composure, Kousei looked around at his meager dwelling. Thirteen slash marks were ingrained into the left wall; he'd been here thirteen days, and today was the fourteenth. Two large black backpacks sat in the far-right corner of the room, each one holding around six leftover MREs, a change of clothes, and ten water pouches. Though at present, one backpack contained the boy's signature gray suit and tie that was his school uniform. After all, Kousei didn't want to just sit in dirty clothes for days on end. The short sleeved white shirt he wore had some specks of dirt from the bunker floor, and his black cargo shorts that matched his black tennis shoes still reached past his knees. Given time of course, he'd outgrow them…assuming his rations lasted that long.

In the far-left corner of the room sat what few possessions Kousei had been able to grab before the missiles had struck: his homework, Kaori's letter posthumously confessing her love for him, some select copies of classical piano pieces, and a few favorite pictures. A lone, dim lightbulb provided modest illumination, and there was only one exchange for it housed in a small compartment on the right wall. Kousei buried his face in his hands…how had everything changed so quickly?!

As if losing Kaori two months ago was not devastating enough, the entire world had come to a fiery end just days before the start of spring. Kousei had been walking home with Tsubaki, after he had encountered her by chance. Although Kaori's last letter had been given to him in February of that year, he hadn't opened it until that day. Tsubaki had just fiercely declared she would be by his side for the rest of his life…apparently, she'd even studied extra hard for exams just so she could have a qualifying score for the same school he wanted to attend! While never requested, Kousei had at least appreciated the gesture. Having her steadfast friendship turned affection, though he hadn't been sure if he reciprocated, was a welcome thing to have in the wake of Kaori's demise.

Until the alarms had sounded.

Even now, Kousei still had no idea what had happened! All he remembered was the sudden blaring of doomsday alarms as the public PA system issued a dire warning that multiple nuclear missiles were heading straight for Japan. Tsubaki and him had looked at each other, wide eyed, and bolted the rest of the way home. Ms. Hiroko Seto and her daughter must've been out shopping, for neither of them had been in the house when Kousei returned. Not that he would've paid much attention anyway. He remembered rushing to find the doomsday bag he had prepared following a national earthquake and tsunami drill three years ago. He remembered bursting out the back door, running into his backyard, finding the camouflaged trapdoor to the fallout shelter, and hurriedly climbing in as the automatic voice on the PA system happily provided a countdown to destruction. There had only been a minute left when Kousei had secured himself in the bunker.

Which, having originally been built for the one person that used to live in this house before he and his mom moved in, could not provide shelter for anyone else.

Not even Tsubaki, who had used the last minute of her life to jump over her backyard fence, sprint to the trapdoor of Kousei's bunker, and bang on it with all the strength she had. Kousei had instinctively opened it, only to see Tsubaki's crying face as she desperately tossed him her own doomsday bag in one last act of kindness.

"I'm sorry for being so mean to you, Kousei!" she had screamed. "Goodbye! I love you!"

"Wait!" Kousei had cried out, reaching for her. But Tsubaki knew it would be no use trying to squeeze into a one-man bunker and slammed the heavy door before shut Kousei could get to her. Kousei had pressed against the trapdoor with all his might, screaming her name in hopes it would somehow make the bunker bigger and be able to fit her in.

But no.

Tsubaki had been too quick in locking the trapdoor and had immediately laid down on it just to make sure her friend wouldn't get himself killed trying to save her. Kousei remembered feeling the extra weight on the door…then suddenly nothing as the missiles struck and Tsubaki was vaporized. He remembered a brief moment of what felt like nothing on top of the trapdoor, then suddenly crashes upon crashes as mountains of debris rained down upon where his home had one stood. A red light beneath the trapdoor blinked angrily; even if Kousei could get out right now, all that awaited him was a slow and painful death from radiation poisoning.

Kousei wanted to cry.

He wanted to scream.

He wanted to shake his fist at the cruel world that had ripped away the girl he loved without hesitation before coming to an end itself.

But right now, he simply felt nothing, and all he could do was sit in blasted silence and contemplate how he was to survive once his MREs and water ran out.

Rummaging through his pile of papers, he found Kaori's letter on the top and took it out of the already opened envelope, This must've been the thousandth time he'd read it. After all, it was the only thing he had left of his beloved violinist Kaori Miyazono, who he'd failed to declare his love to due to his cowardice.

He read it through again, the memories coming back vivid as ever as the words on the page played back her story like a movie in his mind.

Her first time seeing him play, and the mark he had forever left upon her soul.

Her declaration to her parents that she desired to be a violinist so she could play a duet with him.

Her progressively longer hospital visits as her condition worsened.

Her hesitation to introduce herself to him due to Tsubaki's affections.

And then, the three, fateful words he wished he could've said to her the first time they'd met.

I love you!

And that was when he broke.

Tears came to the young pianist's eyes as he folded the letter back up and took out the last photo Kaori had left him. Whether by chance or by fate, it was a picture of tiny little five-year-old Kaori, enthusiastically giving a peace sign to the camera after a piano recital.

With five-year-old him in the back, looking at the camera with a bemused and frankly oblivious expression.

Kousei couldn't take it anymore. The long-suppressed tears began to flow bitterly as he held the precious photograph in his shaking hands.

"Why…," he asked himself in the solitude of his bunker. "Why?!"

As far as he knew, his other friends such as Watari and his stepmom Hiroko were all dead. Nothing remained on the surface except a desolate wasteland of annihilated houses, scorched forests and charred human remains.

His mother was dead.

Kaori was dead.

Tsubaki was dead.

Watari was dead.

Hiroko Seto and her innocent, dainty four year old daughter were dead.

His father, who'd been away on business as usual, was dead.

Even his rivals, Takeshi and Emi, who he'd befriended during a competition of all times…were dead.

He was alone, and there was nothing he could do except ration out his remaining meals, until they were done, and then wait to die.

"Why did all of these things have to happen?! I don't get it!"

He wasn't sure whether he was talking to God, fate, or just himself. In the moment, he could no longer contain his anguish.

"WHY DOES EVERYONE I LOVE KEEP GETTING TAKEN AWAY FROM ME?! WHHHHHYYYYYYYYYYYYY?!"

…..

The Watcher's heart filled with grief as he listened to the music prodigy's desperate howls. The Watcher had observed almost every possible timeline, every event, every tragedy in the multiverse that could possibly happen. But even then, seeing someone so overcome with grief the way Kousei was would never not be painful.

"I know how he feels all too well," Doctor Strange—or Strange Supreme that is—mourned as he observed the boy's despair.

"How debilitating a wound it is," The Watcher said reflectively. "The wound of a broken heart."

"Are you sure you want him on this mission?" Strange Supreme asked. "Granted, you've already proven me wrong once, but I fail to see how a pianist fits into a mission to take down two maniacs with a massive army of robots and titans."

"There's more to it than that," The Watcher said. "Now watch and listen. Kousei's rescuers are about to find him now."

….

Arnim Zola, or the reprogrammed Ultron drone holding him that is, detected a life form amidst the forsaken rubble, and turned his head in that direction. His scanners showed a single, burning heat signature deep underground about one hundred fifty meters north from him and Romanoff's current position.

As he relayed this information to his unlikely ally, Black Widow herself, she looked dubious.

"You're telling me that somehow, someone else survived all this?"

"These drones are state of the art, created by Ultron to be without flaw," Zola answered confidently. "Even if this survivor is not a warrior, I'm sure it is within your Avengers ethic to not leave the innocent behind is it not?"

Black Widow glared at him. "How nice of you to suddenly care."

"Let's go," Zola said, dismissing her grudge.

Originally, Zola and Widow were here to try and find a safehouse where they could safely locate Ultron before taking the fight to him. In this apocalyptic reality, however, any help was welcome. The two allies sprinted over to the heat signature, only to find the survivor was trapped under a mountain of debris. Fortunately, Zola's new Ultron body was covered in weapons that could easily punch a hole through this obstacle.

"Stand back," he warned Widow as he readied the dual blaster cannons on his arms.

Underneath, Kousei jumped back in fear as he heard another resounding explosion just above the door. Were more missiles being unleashed upon any few remaining survivors like himself?! Had the forces who'd launched the world ending devices in the first place come to finish him off?! Kousei knelt down, his tears still flowing, and raised his hands in surrender. If his time had come, he would accept it. Not that he was in much shape to fight to begin with.

He closed his eyes readying himself for the bullet, blade, or club that was surely about to strike him dead.

With any luck, he'd soon see Kaori again in just a few moments after being freed from this hell.

But no…the explosions suddenly stopped. Instead of hearing a horde of angry voices outside, he heard the voice of only two people. A man, whose voice sounded oddly mechanical, and a woman, whose voice sounded almost like Hiroko's. The bolted lock slid open, and as the door opened Kousei found himself looking up at a robot and a tall, middle-aged woman with dark red hair. Kousei gulped.

"Please don't shoot," he begged.

Widow stepped forward. "Take it easy, kid. We're all friends here. I see you managed to survive in this fallout shelter of yours. Have you run out of food or water yet?"

"No ma'am," Kousei said, getting to his feet, grabbing his backpack and climbing up the staircase. "But I would've eventually if you two hadn't shown up." He bowed to both of them. "Thank you very much!"

"No need to bow, young one," the robot said. "I am Dr. Arnim Zola…in an Ultron body that is. This here is my former nemesis now ally, Black Widow of the Avengers. And you are?"

"Kousei Arima," he answered meekly. "I am grateful to both of you for your help."

Then it struck him.

"Wait…Arnim Zola? As in the right-hand man of Red Skull back in World War Two?!" Kousei shouted. "The man who tried to turn our nation into the wasteland we see now?!"

"Yup, that's him," Black Widow laughed.

Zola facepalmed. "You're welcome!"

"So…did anyone else survive?" Kousei asked.

Zola and Black Widow exchanged a downcast glance.

"I'm afraid not," Zola's mechanical voice reported. "Though some were blessed with fallout shelters like yourself, Doctor Doom made it a point to purge as many as he could before he began expanding his conquest. There were also some survivors who surfaced too early, which of course made them ideal targets for his purge."

"Dr. Doom?" Kousei asked. "Who is that?"

Just then, a massive portal opened up behind the three survivors. Black Widow and Zola brought their weapons to bear. Kousei was speechless. A man with dark eyes, straight black hair, and a dark red cloak stood to the left of a giant celestial being. The bigger…person? Alien?...was bald and had bright glowing white eyes. His dark blue cloak covered shining golden armor, and his hands, though gentle in appearance, were very large. Looking right at them, the bald alien pointed a giant finger at the three sole survivors in this one universe.

"Black Widow, last surviving member of the Avengers. Arnim Zola, infamous Hydra scientist and right-hand man to the late Red Skull. And Kousei Arima, renowned piano prodigy and beloved of the deceased Kaori Miyazono…"

He paused.

"You. Have been chosen."