It's always been so erratic.

He remembers as a child how his heart would flutter in a flurry of excitement as he ran through the overgrown greenery. He remembers how it stomped in hardened frustration when he didn't get his way. He remembers especially how he was lulled to sleep by its soothing repetition.

He remembers how it was once normal.

How he was once normal.

It starts off as no more than minor discomfort in his memories —dull, hardly noticeable. He grows, and with him, it's irregularity grew, a persistent intrusion on his feigned normalcy. "It's no longer yours, Katsuki. It's your soulmate's," he's told when he asks, never quite understanding how it's activity increased while he himself did little to cause it. Faster, faster, slower.

Faster, faster, slower.

He often listened to the sound of his soulmate's beat, the pace confusing despite what he knew. His heart —her heart, pounds fiercely against his skin while he sits perfectly still. Katsuki remembers thinking, maybe they're playing; he remembers dealing with the ache so she could enjoy her game.

You take care of your soulmate's heart, no matter what , his mother would always chide. She still does, and he still caters to her needs.

Katsuki remembers it as a game spanning years. Who's heart can beat faster? He would run; he would run and jump and climb until his legs couldn't support him, sending an unhinged beat of his heart snapping hurriedly into her chest. He thought there was nothing that could beat the pace he set —he would always win against her. He was always wrong.

The organ in his chest always seemed to outbeat what he felt he sent to her; if he is a roaring flame, she is an inferno. He never knew why.

His youth sheds and Katsuki notices quickly that his heart never shed its pace; if anything it grew more intense, more erratic, painful. It's like clockwork, he remembers —first thing in the morning, always at sunset, through the night. Wash, rinse, repeat. It stops him in his tracks, his hand reaching for his clothed chest, willing her heart to be calm. He often swore she wanted to win their little game at all costs, for as often as she played.

Minor aches turned major as the throbbing sting traveled from his chest through his body. He was often left pleading silently for relief. Medication, overexertion, redirection -it never quite took the edge off; instead brings him towards more violent methods of liberation.

Katsuki looks at his knuckles briefly, scars and dents littered across them, still fresh in his memory; he'd punch and punch and punch until his fists were coated in scarlet, pain jettisoning from his chest to his hands, and back around. Concrete, metal, drywall; if he could reach it, his fists would make contact.

His reasoning was simple. If she felt something of what he felt, she'd calm the fuck down.

It only ever worsened.

Later in life Katsuki, in brief moments of solace, would recall his youth in scattered images, of how robbed of his childhood he truly came to be. What was a normal heart's pace, he asks then and now, will I ever feel it? His frustration festers, courts his eventual anger at the situation. At her. Does she fucking enjoy my suffering , he remembers wondering -he still wonders. Is she out to prove herself?

And over a bullshit game he was sure she never knew he was playing.

Katsuki breaks.

The pain is fresh in his mind; he hurts, every inch of him screams in protest each time his heart races, leaving the rest of him to suffer under its intense regime. He can never keep up, never outrun her, never outpace. This time, Katsuki clenches his fist, this time it will be enough . He will win, he will beat her, and she will know his pain. Let the games begin .

And then just as he begins Katsuki falls, his legs suddenly weakened and numb. His heart slams against his cage —it's trying to escape. He can't breathe and his lungs scream. He reaches for his chest only to fall flat against it, his arm not enough to hold his weight. White noise consumes Katsuki and he's suffocating. Waves of agony wash over him, sweat beading on his brow, his forehead ground against the floor.

He hears a scream through the static —it's his own, his throat raw as the holler rips through it.

It lasts for an entire hour.

Katsuki remembers riding out the torment until it ebbs into nothingness, the normal irregularity of her erratic beating lulling him into a false calm. Faster, faster, slower. It's was only when the stolen air fills his lungs, him choking on its nihility that his anger dies, the maelstrom of rage courted in his crux diminishing that Katsuki realizes something he berated himself for having taken so long to figure out.

They weren't playing; she hadn't been for a very long time.

It's been years.

Katsuki often wanders, finding a place of solitude where he can be lost in the far recesses of his mind; he spends hours waiting, listening, feeling. He finds comfort in an enclosed stone structure not far from his own home. Here he studies her heart, studies how he's come to know her.

What the hell are you doing? For years he has suffered, for years its only worsened. He wonders if she knows just how fast it beats, how much it hurts. Does she know whatever it is she's doing makes it act this way? What the fuck has your heart beating so fucking much?

Overexertion? The tempting claws of adrenaline? Feeling?

This shit is getting on my last nerve .

Katsuki rakes through his hair with an exasperated huff. He hopes his continual exhaustion is worth it for her, hopes the frustration and anger he keeps bottled deep down is appreciated by she who fate designed for him. He knows he could explode at any given moment; it would be justified. No one could blame him, dealing with what he deals with —maybe a taste of her own medicine would be good for her.

He always feels guilty though; it rushes through him and makes him uneasy, regret rents the space where rage often thrives. Katsuki screws his eyes shut, teeth gritting. He can't put her through that, he knows he can't. You take care of your soulmate's heart, no matter what.

And he has; through his anger at her, through his frustration, through his pain, he has always taken care of her heart to the best of his abilities. He deals because he doesn't know what's going on. He often fantasizes about what could be taking place, each scenario turning out more elaborate than the last. He comes up with an idea. Let's say shits different.

Her heart is his and beats the very same. Can he function? Fuck no. That much is obvious to him. He puts himself in her metaphorical shoes, runs over scenarios in his head. Can he run under these conditions? Can he jump? Can he problem solve? Can he fight? Can he do anything? Again, fuck no , he decides. It would be much too difficult under the pain and stress. But if it was calm...

It's metaphorical he knows, but it helps him to understand something.

Katsuki keeps his heart, housed in her chest, as calm as possible because he doesn't know if that makes all the difference.

All Katsuki knows is that it isn't that simple.

It wasn't as if this was an occasional occurrence, after all, it spans years, a literal lifetime for him. Something this intense couldn't be that cut and dry. He knows her heart well he thinks, having guarded it all his life. All signs point to anxiety, uncertainty, fear. This is something she can't control.

He feels it in the apprehension that claws through his own veins.

Katsuki absentmindedly traces a heart overtop his own, willing the climbing beat to slow. What's fucking causing you this he silently questions over and over.

Relaxation is no more than a mere daydream that hangs tauntingly in front of him, sleep a foreign concept entirely. It isn't ideal, being without either, but he manages for her sake. Was she afforded that luxury, even if only for a moment? Could fear be keeping her from relaxing, from sleeping? Could fear be keeping her moving? Running?

Escaping?

It's big what she's going through, this he's sure. He grips tightly the fabric of his jacket, feeling through its barrier her organ pounding against his skin. It climbing in pace, but still bearable. He can hear a faint thud; it's subtle, soft in tune and near drowned out by the noise around him but its there. Faster, faster, slower.

It's both foreign and familiar to him, a song he could listen to over and over, one he hates and somehow can't get enough of. Because of it, he spends his life in a constant race under the guise of calm, in fear of nothing and somehow everything it seems. It's irritating, yet somehow concerning. Why should I fucking care?

He never asked for a soulmate, never asked to have a heart other than his. He owes her nothing. She puts him through pain and he suffers for her.

If anything, she owes him.

Sleepless nights. Painful days. Depleted energy. Lack of breath. All of it, because of her. Katsuki paddles up a creek without an oar, all to care for the person who took his paddle away.

Katsuki lifts himself from against the stonewall, hands harshly shoved in his pockets. It's nearly night, the chill of the air bites against his exposed skin. It's almost time; he knows, he can feel it. It's like clockwork, it always has been -now, and back then.

Katsuki would wake hours before the sun rises, her heart frantic in its beats. It's a nuisance, beating with a tempo that should not be humanly possible first thing in the morning, a minor discomfort but he can breathe, he can move. It dulls shortly after, beats still paced. During the day it finds a rhythm.

Faster, faster, slower.

It keeps this pace throughout, siphoning his energy, leaving behind sharp jabbing sensations and a lack of oxygen in his lungs. Katsuki finds solace in his bed; he curls into himself, blanket shielding him from the world and he just lies there, teeth grit tightly against each other, nails digging into his skin. He keeps himself like this until the sun-kissed sky meets the shadowed horizon line. Faster, faster, slower.

And when the sun finally goes down?

Faster, faster. Faster.

Katsuki begs for the minor discomfort from earlier that day. He finds himself face to face with a maelstrom of emotions and aches that send him spiraling. He tries to move, a jolt of pain vibrating through him, chest heaving through the tiring beats and needle sensations pricking against his chest. It hurts, it hurts so fucking much and Katsuki screams.

The very action siphons the remainder of his energy, his body finally falling weak to the floor with a resonating thud. The pain only grows, the beat of her heart reaching levels of speed he never thought imaginable. It didn't stop. Please, just fucking stop .

He thought her dying, thought she was going to take him down with her. The only sound around him was the chorus of screams that ripped from him, his mind running circles around his situation, coming to a screeching halt when his mother barrels through the door. Her heart, it hurts! He cries to her in silence.

When he tries to voice his anguish, a scream replaces his words. He reaches for his chest, her heart near visible through his skin and she seemed to just know, pulling his dead weight from the floor and cradling him gently in her arms. It does nothing to ease his pain, but he welcomes it nonetheless. Its a distraction, the pads of her fingers running through his hair a focal point to which he could mask the agony.

He silently thanks her, passing out from the pain alone.

That night defined his life, every day since.

Katsuki huffs; he feels his breathing becoming more labored, his throat tightening —suffocation. His knees are weakening, tension in his legs gone; they're jello. He's not surprised, but prepared, leaning against the wall behind him. He braces himself for what he knows is to come. I can survive this.

Incomprehensible agony. A tightening in his chest forms that threatens to crush his frame and his legs give, unable to hold his weight. Katsuki slides down the wall fast, knees to dirt, the strength of defined arms the only thing keeping him from kissing the ground. Something he is used to doing.

In his affliction, on every occasion, he wonders what the fuck is going on; what the fuck is she so afraid of? Because fear is the only explanation, her only constant.

A question that spans a lifetime brings him from his knees. It's a fight against his own body, against his laboring heaves, against the feverish pace in which her heart leads. Katsuki brings tension back into his frame as he brings himself from the ground. It's slow, meticulous, painstaking but he rises with the wall as his support.

The pain worsens as he moves, but he ignores it; Katsuki finds his resolve.

Whatever the fuck is going on, I'm going to find out.

Katsuki takes a step. It shoots through his body, a knife to his chest but he manages, each step after easier than the one before. He muses her fear to be relenting, but knows it's not the case; his iron will and determination are what's fighting against the agony.

For only a moment, her heart lulls into a calm, the ache ebbing away and returning again. He feels it and wonders. Can she feel it? Does she feel his determination? His need to find answers? Does it bring her a sliver of peace of mind? Katsuki isn't sure but lets a small smile curl in his lips.

He is bitter, he is angry, he is frustrated. He is tired and drained and breaking and when he feels a falter, his steps grow more pronounced. She is the reason for it all and somehow the reason behind his strength.

He hates this, how she affects him in both the best and worst ways.

But was any of this for her?

Katsuki knows nothing of the girl whom fate deemed his, only her heart and its woes. You take care of your soulmate's heart, no matter what . Where was her sacrifice? Where was his protection? Where was his care? Was it really only a one-way street? Fuck that . He holds resentment, contempt, anger in his heart and suffers from every wave of guilt that crashes over him for them.

Still, his feet keep moving.

His newfound journey has nothing to do with her, he decides, or at least not solely because of her; it perhaps never did. Katsuki would be his own savior in shining armor, his own rescuer, his own relief. He would end the trauma with his own hand. If it saves her in return, well that's just a bonus.

He ignores his mind plotting and scheming her safe welfare despite his negative feelings toward her because somewhere deep in the fucks he has left to give, he knows she's not doing it on purpose; it has never been intentional —his suffering, his agony. In her distress, his heart keeps beating, is alive and well, by extension himself. She has to cares, he knows she does.

He keeps this in mind when his anger rains hell down upon her name.

"I'll save us both, " he whispers into the night, still fighting against the discomforting pain. Their suffering, no matter how or why, would end by his might and he would leave her behind, beginning his life anew with a newfound pace and a neutral beat —he hopes.

Katsuki rounds the corner, her heart beneath his hand, beneath his clothes, rising and falling, under the veil of his skin. He clutched it tightly. Faster, faster, slower.

Faster, faster, slower.

It's not for her, it's only to relieve the pain.