In the manga, Shion actually refers to Mion with her name (i.e. calling Mion "Shion") in these parts of Eye Opening, because, as I have mentioned in other prompts, the Shion that fell in love with Satoshi was originally called Mion before the current Mion was mistakenly tattooed as the heir. During the latter parts of Eye Opening, the one we currently know as Shion reverted to calling her sister as she did when they were children, before everything basically went wrong. I kept them in their current names for the sake of clarity during this prompt, though.

June 26th, 2021

If this really were a story, some tragic tale of love and betrayal in the far-off days of Japan, it would be about now that she would come to herself, Shion thought vacantly as the sounds of her sister's screams and the slow drip-drip-drip of blood filled the torture chamber. It would be right about now that Satoko would stir weakly, cough out some quip about her being not strong enough to beat her, and Shion could be properly sorry.

Not believing in Satoshi's return, she'd forgotten the one last favor that Satoshi was counting on her for. He was waiting for them both, but in order to be worthy of him, of that gentle presence that she loved so much, Shion needed to keep her promise to him. Satoko needed to become stronger, and Shion needed to protect her in the meantime. But from the very beginning…she'd never done a thing to keep her promise.

"Sato…ko…" she choked, crawling across the expanse of the tiles where she had collapsed. Her hands were stained, filthy with the younger girl's blood, and more of it soaked into her knees as she reached the cross and reached up. "Satoko…"

Deep, bloody cuts marred both of Satoko's outstretched arms, the solid wood beams they were anchored to looking like a butcher's block. They oozed more blood as Shion touched her, and she choked with more tears, remorse welling up in her like a flood as she clutched the dangling body and cried, wailing her grief and her guilt to the vast echoing space around them. She clutched the limp body, embracing her, Satoko's head nestled against her chest like it never had been in life.

She slumped to all fours before the corpse, her sobs drying up as emptiness filled her heart. No one would come for her. Satoshi would never forgive her. If even the presence that loomed behind her shoulder abandoned her –Satoshi, Oyashiro-sama, or herself, it didn't matter– then what was she? What did she have left, except a bitter, desperate wish for blood and tears and pain, and none of it her own?

None of this had ever been for Satoshi. Shion knew that now. Killing Oni-Baba, Kimiyoshi, Rika, Satoko –that was never what his gentle soul would have wanted. Satoshi was kind, nurturing, fiercely protective of those he loved, but otherwise shrinking back and down at the first sign of trouble. If it was just him being hurt, if he was taken and trapped alone, he'd probably apologize for the inconvenience as his blood soaked the racks of the torture chamber that she had used, the very same place he might have been killed in all those years ago. She could just see it, his shy face twisted by pain as they pulled his intestines out of him, his shaky smile and tears as he apologized for getting their floor dirty.

Unforgiveable.

Unforgivable.

Shion was a demon now, with no tears, no soul, and no pity, and as she had been unable to do then, she would act in Satoshi's place now. That was what good couples did, was it not? Satoshi could be the gentle one, the caring one, the one with soul. She could be the iron fist inside his velvet glove, the steel beneath the silk, the brawn to his beauty. Shion could be the ruthless one, the murderous one, the one who was a threat.

Her revenge for Satoshi was something that Satoshi never wanted for a second. It was for her own satisfaction. And if she couldn't face him anymore…then at least she would close the curtain in a way she could approve of.

Those were the thoughts that filled Shion's mind as she lured Keiichi down into the basement, as she bashed his head in amidst her sister's screams, as she dragged him to the table to torture him to death.

I won't ask for anyone's pity. I won't act like a tragic princess. I will become a murderous demon with absolutely no room for pity.

Of course her sister and Keiichi would ruin everything. Of course they would. Why would it be any different? They'd ruined everything with her before, made her think of Satoshi again, woken up the demon that slumbered in her heart, caused all these other people to die. How dare they be together when she was forced to be apart? How could Mion betray her by falling in love, when she knew Shion had lost the one that she loved more than anything? How could she flaunt her crush on Keiichi in Shion's face like that?

She had just enough mercy left in her to spare Keiichi, but that was all. His wheedling words had gotten him that much, in the end. And maybe…maybe she could understand why Mion had fallen for him, when he refused to believe that she was Mion or Shion, when he protected both of them in his heart like no one else ever had, that he refused to blame one or the other, that he refused to believe wrong of either one of them.

But Mion received no such mercy.

Maybe her earnest words and tears might've moved the real Shion. Maybe her insistence that even the Sonozakis didn't know who was casting the curse or why might've worked with Shion before she had lost everything, before she had been abandoned by Satoshi's spirit, by even her own, in that bloody torture chamber with Satoko's corpse. But that Shion was gone now, replaced by the demon.

Electricity arced between them from her taser, and Mion slipped silently into the well with a flutter of her white kimono, silent as a ghost before she even died. Her eyes were empty, dull, pleading up at Shion as she watched her fall, but Shion was stone-faced.

Once I've killed Shion, it will be finished. That's what I decided. If I can't accomplish that…then what was my existence?

What is my life, a life in which I threw away everything to avenge Satoshi?

At the very end, you say these things that mess it all up. But that would mean everything I've done…wasn't revenge. It wasn't anything.

It means I was just…

…possessed by the fifth year's curse.

"Apologize when you see Satoshi in Heaven." Shion said as she turned away, heading back to the darkened cells. "I can't go to Heaven, so I can't tell him I'm sorry."

10.33 PM, USA Central Time