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Izuku’s most visible soulmark has always been a spectacle. Inspiring speculation and wonder, the blue flames curling around his left eye have been a question unanswered his entire life.
A question now answered.
The same blue flames roar around him, the forest going up like kindling. His shattered arms throb as the heat sears them, his skin tight across his face and back.
Severe shadows flicker across the figure in front of him. Coat flapping in the fire’s wind, Izuku’s soulmate approaches, his hands shoved in his pockets and posture casually slouched.
Blue light throws his face in sharp relief, glinting off of staples and piercings and illuminating the green lightning twining around the man’s left eye.
“So. It’s you, then,” the man drawls. “Twenty-three years without a soulmark, and then one day, it just pops up. What a pleasant surprise.”
Izuku swallows and takes a step back. The fire has surrounded the two of them, cutting off all escapes. One For All hums beneath Izuku’s skin, called forth and boiling near the surface, ready to explode into action.
“I’ve known it’s you for a while. I watched the Sports Festival, especially your fight against Todoroki. I know my flames when I see them. And the way you hurt yourself with your quirk?” The man’s eyes rove over Izuku’s busted arms, a probing survey which sets Izuku’s teeth on edge.
All the same, Izuku can’t help staring at the man’s injuries as well. Large swaths of the man’s skin are burnt and held together to his healthy skin by thick staples.
“You’re like me,” the man concludes, one corner of his mouth twisting up into a tooth-showing smirk. “I had doubts at first—never put that much stock in something as silly as soulmates. But now? I’m a believer. We’re the same.”
“We are not the same,” Izuku snaps back.
“Are we not?” The man steps closer, pulling one hand out of his pocket and holding it out to Izuku. “Come here and let’s find out.”
Izuku shakes his head. “No.” He glances left, right, behind himself, behind the man, looking for any gap in the ring of flames around them. There is none to be found.
“What? You don’t want to know your soulmate?” The man snorts and shakes his head, soot drifting down off his hair. “Come here—let’s dance.”
One For All glows to life, jarring his broken bones but flooding the rest of his body with power. The risk of jumping through the flames is worth it. He just needs to be fast, in and out and running before his clothes or hair have a chance to catch.
He takes off sprinting for the ring of fire—
And skids to a stop as a thick column of blue-white flame cuts him off. He turns, and another column is already sizzling by him. He turns again, looking for another escape route, only to come face-to-face with his soulmate.
“I’ve got you.” The man reaches up and grabs Izuku’s head between his hands, his staples catching at Izuku’s hair. Already Izuku can feel the first-fusion blurring of the lines taking over, the man’s hands twin points of warmth that sinks deep and spreads across Izuku’s body.
The man leans his head down and presses their foreheads together.
“Let’s get to know each other,” he whispers.
Izuku doesn’t remember his first-ever soulmate first-fusion—he and Kacchan were toddlers when it happened. He does remember his second, which had been a surprise to both him and Uraraka, happening when she used her quirk on him to keep him from faceplanting after tripping.
This first-fusion is nothing like that time. That time had surprised both him and her, and they had barely stayed together for heartbeats before falling apart in surprise.
This time, Izuku knows what’s coming. This time, it’s not a serendipitous coming together of partners.
No. This is a battle of wills.
The hands go first, blurring and fading. The sensation claws its way up Izuku’s arms, taking away the pain of shattered bones. It fizzes through his core, eating him from the inside out and working its way down his legs.
They mix and melt together. Bleeding and blending, they sink into one another, their souls winding around each other. It’s push and pull, shove and tug, even as they’re poured into one body, one mind, two joined souls.
It should be beautiful, and it is. They stumble on unsteady legs, taller, thinner, stockier, stronger than they were. Staples tug on skin and hands ache with old injuries. Smoke and ozone wreathe around them, a pungent perfume strictly theirs.
Their form settles. They take one step forward and throw their arms out wide—this is them. Screaming jubilation at the top of their lungs, their shoulders shake with invisible sobs. Their eyes burn—they need to cry, they can’t.
Their mind is a tug-of-war. Touya meets Izuku, Dabi meets Deku, and—
Understanding.
But not.
Izuku stumbles forward, reaching up and tugging on their hair. Curls, it’s curly, but it’s coated in some substance, something powdery and gritty—
Soot drifts down off his hair and Touya stares at his hand. Crooked fingers, staples and burns, he joined the League to steal his soulmate and he succeeded.
Their fire dances around them as feelings, knowledge, memories dance through their head. Their father, their mother, Endeavor, All Might, their skin consumed by flames and their bones pulverized by raw power. Each one heir to a different legacy, one chose and one cast away.
They tug at their face with their fingers, eyes burning but tears unable to come.
“Do you see it now?” Touya asks, voice cracking and snapping like the flames around them. “We’re the same! We’re the same, you and I!”
Izuku protests, and they almost fall apart, but Touya clings and clings and clings, refusing to let him go. He grips so tight that Izuku almost goes under, almost sinks into the fusion.
And so he grips back, clawing and fighting for control.
“We’re not the same,” Izuku hisses. “I’m not a villain.”
“Oh, you act like hero and villain are innate qualities someone has.” Touya drips disdain, the emotion washing over Izuku until he feels it like his own. “When you could be the villain and I could be the hero just as easy. It’s all a matter of perspective, you see?”
And Izuku does see. Touya’s thoughts are Izuku’s thoughts. Touya’s feelings are Izuku’s feelings.
Izuku’s feelings are Touya’s feelings, too. They bleed into each other, cross-contamination of the highest degree. Terror that slicks their palms with sweat, bloodlust so strong their heart beats faster in anticipation of the fight. Vengeance and ambition tie knots around each other until Izuku can hardly separate his own drive to expose Endeavor—
No. That’s not him. Is it?
But it is them.
“Come on, Izuku,” Touya croons. “It’s already happening. Let’s just get along.”
“Why do I have to be the one giving in,” Izuku spits, a rage rising in him strong enough to match the conflagration around them in violence. “Why do I need to be the one to submit?”
That rage carries Izuku, swamping Touya. They spin around on their heel and, with one sharp gesture, part the veil of flames around them.
“So it’s true,” they whisper, staring, awed, at the gap in the flames. “Quirks do evolve in fusions.”
They know—but they don’t—they’ve experienced it before, with Uraraka, the extension of control, the finer ability, the increased strength.
“We’d be unstoppable,” they whisper. They stagger one step forward, dark chuckles rising from their throat. “He wouldn’t be able to touch me.”
Which ‘he’ do they refer to? Endeavor or All For One? They can’t answer that question.
All they know is that it’s true—Cremation and One For All weave together, twin stars of heat within their chest and hands.
“Do you see?” Touya whispers. “Do you see how good it could be?”
“I’m not a villain,” Izuku hisses back. “I won’t be a villain.”
But that’s such a narrow way of looking at things, isn’t it? Villain, hero, black and white words addressing a grey and grey issue. They don’t have to call themself a villain at all—that’s a label the rest of the world puts on people.
No, no, no, that’s—that’s not it. They want to help people. They want to save people. Villains don’t save people.
“Nothing says we can’t save people,” they whisper. “Wouldn’t killing him save lives? Couldn’t we do more if we weren’t shackled to the hero system and its laws?”
It’s true—they could do more. As Izuku, he had to attend school, was too young, had to learn how to use his quirk and hone his skills. As this—
As this, they’re older, stronger, their skills a synthesis of the abilities of both. Their intelligence, their knowledge has been combined. All pieces have been added, summed up, increased. They are more than they were.
“We’ll miss our rendezvous,” they whisper.
Without even realizing what he’s doing, Izuku submits.
Gehenna takes their first step as a fully-integrated fusion.
“Where the fuck is Dabi? He can take his time, it’s not like we need to be getting out of here.” Twice dodges away from one of the hero brats—from their bastard younger brother—from Todoroki—
A surge of protectiveness overshadows the stirrings of hatred. That is Shouto, their brother, their friend. Their paths may have diverged, but that doesn’t mean they will let him get hurt.
A quick glance over the fight tells them a few things. On the League side, Toga, Twice, the Noumu Shigaraki insisted on sending with them, and Compress face Shouto, Shouji, and a rampaging Dark Shadow.
“I wonder if it will still listen to me,” they muse, before calling forth their fire.
The inferno bursting forth from their skin comes easier, stronger, hotter than it ever has before. With dexterous hands, they weave the flames between the League and the hero students, separating and pushing the two groups away from each other. A pillar of flame rises up around Dark Shadow before subsiding, the quirk reduced to a ghost of its normal power.
All eyes turn to them as they step into the open.
“Sorry I’m late. I needed to take a detour and … pick someone up.”
Twice gives them a thumbs-up. “Whoa! You look different! I like it.” A moment later, “You got uglier.”
“What do you mean by pick someone up?” Toga, asking the important questions. Blood streaks across her sweater and coats the blade of her knife.
“Didn’t I tell you I was here to find my soulmate?” Gehenna turns their head to the side, letting everyone catch sight of their joined soulmark.
The gasps they hear satisfy something deep inside them. Their lips twist into a slight smirk, pushing until the expression begins to tug on their staples.
“Midoriya?” Shouto’s voice breaks down the middle.
Their expression shifts, bitterness darkening it even more. “Sorry, Shouto. I’ll see you around.”
Kurogiri’s warps open behind the League. In the next heartbeat, a glittering laser cuts through the clearing, smashing into Compress’ face and breaking his mask off. Two blue marbles fly out of his mouth.
Everyone in the clearing moves at once. Shouji wraps a hand around one marble, stealing it away from Twice, while Gehenna’s arm snaps out, green sparks trailing from it, and snatches the second marble from Shouto’s fingertips.
Compress releases his quirk, and where they held a marble, now their hand wraps around Kacchan’s neck. Something simmers between them, the familiar pull to fuse that comes with every soulmate’s touch, but there’s a wall between them. Gehenna can’t fuse with someone they’re only half soulmates with.
They lean forward, over Kacchan’s shoulder, and grin. “You could come, too!” they crow, reaching out with their right hand, stretching for Shouto’s hand and linking their fingers.
Shouto pulls away, wide-eyed horrified and falling to the ground. In Gehenna’s hand, Kacchan begins to struggle, so they step backward through the portal.
The last thing they see before darkness swallows the scene before them is Uraraka, wide-eyed and panicked, pulling out of Shouji’s grip and running for the closing portal.