A/N: ALL ABOARD THE MUGEN-- I mean, ANGST TRAIN! Obviously, the Kizuki (and Nezuko) won't be in this one, but they will be in the next!

Also! Tanjiro's is kind of related to canon, but kind of not -- for one, nobody dies in Mugen Train/Infinite Fortress.

--

Tanjiro:

You'd heard the awful news immediately and rushed to your boy's aid. You were worried sick that he wouldn't be able to contain himself. Once you got there, you saw him crouched over Nezuko, snarling and... "Feral," you'd whispered in horror, Zenitsu gripping your arm protectively.

You watched as she cried, begging him to come back. She'd just become human again, and yet now Muzan found it fit to turn Tanjiro -- the cruelest irony. You called out to them, begging him to come to his senses.

He froze, hearing you. His head slowly craned so that he could stare at you, his bright red eyes wide and locked onto you. He growled again, his claws gripping deeper into Nezuko's shoulders. She swallowed her cry of pain and tried to get his attention again.

Suddenly, he stopped. His hands left her shoulders and gripped his head, and he let out a howl of pain. He grit his teeth together, thrashing from side to side before he finally fell limply across Nezuko -- and she immediately hugged him, calling for Tamayo to help.

You sagged against your teammate, scared to death, but relieved -- your Tanjiro would be safe in her care. You couldn't stop the tears that dribbled down your face as Inosuke came to lead you away.

Zenitsu:

Zenitsu had gotten closer to the explosion than he'd thought, and he'd accidentally ingested some blood. Now he was snarling, drool dribbling past his sharpened teeth as he struggled to bite you. You were crying, begging him not to do this.

Your grip was sure, but he was stronger -- and faster than you. More than once the sword in your hand was pushed back, but you resisted. The blade was cutting through his hands, but he worked through the pain, growling dangerously at you.

As a last resort, you screamed. "BABY!" One of the many nicknames you gave each other slipped out, and it stunned him for long enough that you could kick his hips away, flipping backwards.

You were panting when he got up and looked at you. He opened his mouth once, twice, but then clamped it shut, his golden eyes flickering with something unseen.

Then his eyes widened and he opened his mouth again, struggling. "(y-- y/n)?"

You collapsed to the ground, your exhaustion catching up with you as he rushed for you, his shaking arm the only thing keeping you from a painful fall.

Inosuke:

You were there when he was turned. You had to watch as he writhed and screamed for an hour. You were forced to fight him off when he inevitably turned against you. The boar mask fell off his head when he lunged at you, snarling and drooling.

You couldn't stop crying as you tried to fight him off, but after a while you began to grow weak. You begged and pleaded, but nothing could snap him out of it.

The pain exploded through your shoulder as he bit into you. It was so intense that you could do nothing but scream as he tore into your skin. Eventually, you blacked out, with only the sight of your boyfriend's crazed, vibrant green eyes as the last thing you'd ever know.

Giyuu:

Giyuu had finally succumbed to the temptation and had fallen. When you saw him next, you could hardly recognize the man you'd loved. The tips of his hair had taken on a dark cyan hue and he'd grown a horn on the side of his head. When he saw you, his eyes widened before they grew sad and he looked away.

You couldn't even speak, you could only watch with tears burning your eyes as he walked away, his nichirin sword glittering in the moonlight on the ground before you.

From then on, you began to get more serious in your training. Your parents were devastated at the loss and allowed you to go harder. You were determined to be the one to either kill or change your boyfriend back. Tanjiro joined you in this quest, both of you heartbroken.

Kyojuro:

You'd heard the news and were horrified. How could he? How could he have fallen so far? When you next saw him, you could hardly recognize your sweetheart. His hair was long and wild, his eyes sharp and lifeless. He gave you a remorseful look and turned away, leaving the area with Akaza giving you a taunting grin.

Ever since then, you'd trained yourself harder than ever. You had to be the one to take down the newly-recruited Upper Kizuki Five, and if you couldn't, you'd still die trying. You could never forgive yourself for allowing this to happen.

Muichiro:

You'd never thought Muichiro would be the one to turn, but apparently he still loved to surprise you, even as a Kizuki. You were stunned as you beheld the new Lower Kizuki One standing with Kokushibo, his face blank. You could faintly discern some sadness in his gaze as he leapt at you.

The two of you fought for some time, you channeling your sadness into your anger. You were both matched blow-for-blow, all the while Kokushibo stood some distance away, watching.

After some time, you had the chance to take the final blow. You had Muichiro cornered, but he wasn't fighting back. He just looked at you, almost as if he was saying, "Please kill me."

You didn't. You sheathed your sword and turned your back on him, running off. You didn't want him to see the tears shining in your eyes while you cursed your inability to kill him.

Shinobu:

You rushed with Tanjiro to where Tamayo lived, worried out of your mind for your girlfriend. Last thing you'd heard of her was that she was going to battle a Lower Kizuki, and only hours later you were getting word from the boy that she'd begun her transformation and very well could die.

As soon as you got there, you rushed for her room. Tamayo was already there, a saddened look on her face. Apparently, the wisteria poison in her system had begun to kill her as soon as she turned, and there was nothing to be done. Shinobu would die.

You were able to get a moment alone with her, and even though she was unconscious, she feebly squeezed your hand back when you tried to comfort her. You stayed there for half an hour until her death. As soon as Tamayo slid the sheet over her face, you collapsed against Tanjiro and Nezuko, weeping inconsolably.

Gyomei:

Only fitting that the strongest pillar would only fall to Muzan. You hadn't been near him when he'd been forcibly turned, but you heard the screams -- and when you rushed to his aid, you found him writhing on the ground in agony, and Muzan was gone.

You stayed at his side, pleading with him to get through this -- and when he regained consciousness about an hour later, he croaked out your name and held you close. You cried into his chest, apologizing for letting this happen.

The two of you escaped the battlefield and you went to Tanjiro, begging for his help in changing Gyomei back. He immediately empathized with your situation and promised to help.

Sanemi:

Sanemi absolutely didn't want to ever be turned. In fact, he told you to just kill him if he ever became a demon. You didn't exactly want to honor those wishes when you and Genya found him after a fight gone wrong, now sporting fangs and slit-pupil eyes.

When he saw Genya, his desolate expression turned to rage, and he screamed at you, demanding to know why you brought him. Genya tried to placate him, but he just swiped his new claw at him instead, leaving deep rivets across his face as he fell back.

You could see tears in his eyes as he pleaded with his older brother, but Sanemi didn't want to listen. He ran off, leaving you both behind.

Yoriichi:

When you heard the news, you ran for your boyfriend. Sure enough, Yoriichi was fighting the influence of Muzan. You called out to him, and his head snapped over to stare at you. He begged you to run before he collapsed to the ground, hands clawing at the earth and drool bubbling over his teeth.

You refused, determined to stay at his side. You stayed with him as he fought it, thrashing and yelling and growling. When at last several hours had passed (and only half an hour since he'd gone limp), he opened his eyes and looked up at you in hurt.

You wouldn't give up on him. If Muzan turned him, surely there was someone who could turn him back. You helped your love away and started to form a plan of action.