Warnings: choking, violent arguments, physical violence, guns, Reborn being super angry, Tsuna's lack of self preservation/suicidal thoughts

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Sorry for everyone waiting on a Coi update, I am still working on it but it's probably not getting an update for a while.

This can technically stand alone, but it's missing a lot of the wider context from the original (Foxtronic's The Sin of the Sky. It's a good read, you should check it out!) This is an alternate of the first chapter of that. The full thing is Tsuna/Arcobaleno, but mine is... not.

Most of the dialogue is copied directly in order to preserve the flow of the scene, and any tweaking of that was a personal preference for formatting or phrasing. This goes for ALL of the Italian as I do not speak/understand it myself. Hopefully Tsuna being a girl doesn't change any of the word endings? Feel free to correct me!

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She had no idea what she was doing. Tsuna was doing it anyway, regardless of how much she knew or didn't, because after years of existing, doing something was better than waiting in vain. Especially when nothing else was left to do before she died. She couldn't let Reborn watch her waste away, especially not because of something she did to save him. Damn her selfishness.

"What."

"I said get out." Tsuna said the words, half-aware that she was actually making those words with her own lips, yes. They didn't tremble on the way off her tongue, like Tsuna expected. She sounded firm. Exact. Fierce.

Like Reborn had taught her to be, against the Dons that thought she should be spitting sprogs out of her vagina because her value was in her womb, holding the genes they wanted - but male next time. The same Dons that called Reborn feral, wild, for being exactly what he said he was. Reborn was the Strongest Sun. And somehow they thought she, now-Vongola Decima, formerly-Dame Tsuna, seduced him into being at her beck and call. As if anyone could.

There was a moment of silence, then the sound of leather shoes moving across the carpeted floor. (But only because he lets you. He only makes noise if he wants to, remember?) She heard a click, felt cold metal dig below her high ponytail.

"Try again, Dame-Student." There it was. There was Reborn's furious refusal. One wrong step and he would actually kill her because how dare Tsuna try to command him, the one person who should know better. The student who had always made the right choice when forced to choose between what she wanted and what someone else needed. And Reborn did need his freedom, desperately. Yet she was asking for it anyway.

Tsuna turned around with no resistance, the muzzle of the gun sliding to rest against her forehead easily. She looked up (and up, because Reborn as an adult was both physically imposing and absurdly attractive, compared to her more unimpressively compact frame) to meet Reborn's yellow-edged eyes. Fuck.

She couldn't let her gaze falter, not even once. It wouldn't stop his uncanny ability to read her mind, no matter how alarming the Flame edge in his irises was. The very man threatening her now was the same one that had taught her about the dangers of Raging Elements. He was also one of the few she still couldn't beat, Raging or no. Double fuck.

No going back now, he'd have no mercy either way. It was a matter of making it out alive. Tsuna wasn't entirely sure she wanted to. Nonetheless, "Leave. Go away. How many ways do you want me to say it? What about in Italian? Uscire dalla mia vita per sempre. Is that clear enough for you?"

His hand was on the nape of her neck, pulling her even harder into the gun. Tsuna knew it would bruise black, if she lived through this. Better a bruise on her than what was waiting for Reborn otherwise.

So selfish.

Reborn's eyes glowed like an unholy abyss, scorching heat against her skin even as it stole life-warmth from everything else. His fury seared against her Flames, tucked up as tight as she could manage. It'd been so long since she'd been able to relax around him, knowing a moment of inattention was all he needed to finish the Bond. Tsuna couldn't, wouldn't survive leaving him. Or worse.

As the gun shifted to her temple, Reborn leaned down to press their foreheads together, holding her completely trapped in his hold, in his eyes. She couldn't back down. This was for Reborn, and she couldn't let him stop her.

"You listen to me, il mio bambino cielo." His voice was a rumbling purr that caressed her lips even as the words cut soul-deep. "If you think for even a second that I wouldn't burn the world to ash before I was forced from you, you've forgotten what kind of monster I am."

The wall met her spine, the edge of a painting digging in below her shoulder-blade, and then Reborn's hand was snug against her throat. Not choking, not yet. But Tsuna could feel his fingers digging a little deeper under her jaw with every breath. He could feel every swallow, every gasp as she dragged it past his palm. Could feel her racing pulse under his thumb.

It took a second for Tsuna to realize her hands were holding his wrist. With every shaky inhale she traced across the skin on the back of his hand, but she wasn't trying to pull him away. It was probably the only reason he wasn't actually cutting off her air flow. At least her subconscious wasn't stupid enough to go for his gun hand.

So selfish, to take advantage of him like this. He never touched her when he was calm.

But Reborn was still talking, "Did you think I was a child, Tsuna? Did you think I would curse at you, yell like all your little Guardians do, then leave? That I wouldn't put a bullet before I left because of what? Fondness? I am not kind, bambino cielo."

He tightened his grip, pulling up just enough so Tsuna was stretched up on her toes, barely on the ground under her own power. Her flames fluttered in her grasp, wanting to reach for him. Crying for such strength, such passion. No.

"I am The World's Greatest Hitman. My hands are dyed with so much red that you would be sick if you could see the way they stain everything I touch." He paused, a cruel smirk curling his mouth, "But isn't that what you want, Tsuna? You want me to stain you, to hold you down and mark you because no one else can. Not Mukuro, he thinks you too precious for his bloody embrace. Not Kyouya, because he can't pin you unless you let him." Reborn pressed harder, his molten eyes victorious as he dragged her higher, "Are you letting me, Tsuna?"

She might be suspended by the hand around her throat, but the Decima refused to kick her feet helplessly, to close her eyes. She had to finish what she started. It was for his own good. Wasn't it?

You're so selfish, Tsuna.

His flames pulled at the grip she had on her own, coaxing, seducing; knowing there was a weakness and it was just a matter of finding it. Tsuna couldn't let him find it. She was running out of time. She had been running out of time for years. Why was he so determined all of a sudden? Tsuna had been dying for years, the only difference was she could feel the symptoms creeping up on her now. Reborn hadn't noticed, had he?

"I am selfish. I am possessive. I am a sadist and you are mine, idiot-student, idiota bambino cielo. You have been mine since you broke my Curse. You have been mine since you refused to let me die in a gutter like a dog. You are mine to protect, you are mine to teach, and you are mine to keep." By the end, Reborn was growling in her face, his body crushing hers against the wall and the gun tracing down her cheek lovingly. He held it between their mouths for a moment, almost kissing her through it.

And the whole time his Flames… Reborn's Flames were searching for the place where they were already hidden, so he could flood the Bond into realization. As long as he didn't notice, Tsuna would be fine. She would. She couldn't let him claim her no matter how much she wanted it.

She couldn't watch him leave her. But she had to make him. If he saw what she'd done to herself, Reborn would burn the world, just like he said he would. If he had to watch another Sky leave him for the Arcobaleno Curse, nothing would survive. Especially not Tsuna.

Selfish, selfish, selfish. Just give up, give in to him.

Reborn would choose to leave her, unless she made him.

The toxic yellow ring was getting wider. Her continual refusal of their bond was only driving his Rage into new heights. Maybe Reborn would actually kill her after all. If he thought she was his, her life was his to end whenever he felt like it. Would that be better or worse? Tsuna wasn't sure anymore. But that could be the lack of air getting to her.

But Reborn just wouldn't. Stop. Talking. "I would have happily killed your Sun, your friend, if I knew you wouldn't run from me because of it. I would have killed him in the most painful way possible for daring to have his Sun in my Sky."

He stepped back, lowering her to her feet and then, finally, releasing her throat. She collapsed on the floor, trying not to cough as she rolled her Flames up even tighter. Reborn hadn't stopped seeking the patch of his Flames in hers for a moment, and she felt oversensitized and woozy. Every inch of her screamed to give in, to let him have her, to claim her Sun.

Her caramel eyes watched him shrug his sleeves back into place. Reborn was once more immaculate, the bloodthirsty monster tucked back behind the mask until the next time someone pushed The World's Greatest Hitman too far.

The last of the yellow in his eyes retreated in the next blink, and he smirked with a normal level of sadism. "Don't bring this up again, Dame-Tsuna. I won't be so kind next time." He tilted his head, "You might find yourself out of an official Sun Guardian."

He crossed the room silently, pausing with one hand on the door handle. "And if I get an inkling that you'll run regardless, well, there won't be anything holding me back anymore."

Reborn's Flames stroked Tsuna from head to toe one last time, curling a possessive ribbon around the blooming mark on her throat. The tip rested on the left pulse point, where his thumb had pressed so firmly before. Tsuna couldn't hold back the shudder.

How did he know? How did Reborn always know? Had he been playing this whole time, letting her think she could hide something that was his from him? He knew exactly where his Flames lingered.

"Don't overestimate yourself, il mio bambino cielo."

And he was gone.