Kairi tries to stand. Destiny's Embrace flickers to her for an instant and then vanishes as if unable to sustain itself.
Riku watches her struggle to get to her feet, gratified in contempt. She had a home and an army of people who loved her, and she threw it away because she got tired of living in an ivory tower like the princess she is. At least Naminé had a reason to be sad.
Naminé could have been somebody real. She was powerful in ways even Master Xehanort can't match. And he wasn't kidding about remaking her. It would've been painless—well, it would have been easy if Kairi chose to cooperate.
They always wanna be martyrs.
"Don't be difficult," he calls out. "If you dawdle in a Corridor too long, Heartless will catch your scent."
He catches a soft glare from under her disheveled fringe. Her shoulders shake with the effort of catching her breath. "Your boss won't… won't be happy if you let Heartless get to me first."
"Master Xehanort doesn't need to know. The Heartless won't be able to kill you before I track you down… but you won't like how long it takes me."
As if to sell his point, the Corridor rumbles threateningly.
And what an immense pleasure it would be to let the Dark World take its due course. But it suddenly seems like a waste of time and energy better spent investigating—punishing—this so-called mole in the Organization.
Kairi struggles to one knee and halts, unsteady. Blood smears the tattered front of her dress and spreads into a growing smudge underneath her. "S-Saïx would know. He knew I was on the ship. He'd wonder what happened to me."
Riku laughs. "Given the choice between me or Saïx as your retinue, you're better off with me. Especially after his trip back to the lotus chamber. You can ask Naminé about that. Oh, wait."
"We don't have to do this. You don't need them."
"What I do is up to you, princess. What's it gonna be?"
She staggers to her feet. Bleeding, precious seconds wasted. She calls Destiny's Embrace forth into a two-handed grip.
Riku smirks. The Guardians would be beside themselves seeing this. Their do-no-wrong golden child, beloved by Kingdom Hearts itself, hacked away in pieces as she goes down fighting with nobody to protect her. Fine by him. See how she fares without the luxury of other people fighting her battles.
So he doesn't hold back.
Charged with darkness, Soul Eater's swipes and spells send her ducking and reeling like a marionette with its strings caught in a behemoth's teeth. She forces him twice to deflect shotlocks and slashes: first by his surprise; second by his interest. He observes as she unhands her keyblade to attack; it swerves and swells around her as if by its own free will. Her aura of light seems to act as a phantom limb to control it. Fascinating.
She stumbles for every inch of ground regained. When she falls, Riku waits. He taps Soul Eater's blade idly, waiting to see if she'll rise again. She does. Riku watches a nick on her left cheek mend itself. A modest display of the protection Kingdom Hearts offers its favorites.
He makes sure to replace those cuts until they stop mending themselves, to say nothing of the wound carved from thigh to collarbone. She remains on her feet for almost a full minute after the healing stops. Impressive, admittedly. Once a well-placed Dark Aeroga sweeps her feet out from under her, though, she doesn't rise again. Her legs buckle when she tries. He's pleased to see even someone as privileged as her is not immune to his strength. Strength for which he, unlike Kairi, has suffered.
But she is either too stubborn or too stupid to accept her loss, so she summons a barrier between them.
Riku looks it up and down up close. A well-constructed spell. He regrips Soul Eater like a club.
The barrier shatters under his blow.
"Wait," she gasps, clutching at her chest. "Don't do this right now. Not yet."
He chuckles. "Not yet? You're past due."
Her eyes glaze. She convulses, gasping out something he doesn't understand. He brandishes Soul Edge.
"Stay out!" she cries. "Don't burn him—" A full-body shudder forces her to her hands and knees. That light-filled aura of hers blinks out.
He brings down Soul Edge's hilt over her skull. Before it makes contact, another barrier blows him off his feet.
He catches himself in a roll when he hits the ground, on his feet an instant later.
Another fiery barrier—no, a shockwave, this one as hot and blinding as a curtain of embers—ruptures out of her. Riku throws up his own barrier a fraction of a second before it reaches him. He wipes char and soot away from his eyes in anger and disbelief. Is she serious? Who does she think she's fooling with this little display?
She convulses again. The cold Corridor air turns balmy. Her aura presses up against his barrier. Half-opaque, half-alive, liquid fire sizzles on its surface. It seeps up from the darkness-covered ground around her. It climbs from her hands, up her arms, toward her face. The floor cracks light spilling through from underneath.
Riku summons Heartless to hold the Corridor together, but they spawn just to catch fire and die back into the shadows. Her aura turns opaque, blinding him and trapping him within his own barrier. He strikes the shell in frustration. The white-hot curtain ripples and intensifies in response. He paces.
He examines it, feels the heat press in on him. Observes no area of weakness. No way to brute force his way through. He is utterly cut off from Kairi on the other side. The light dizzies him, weakening his hold over the darkness. It weaves hairline cracks on the crown of his barrier. The Corridor rumbles.
"Do you want to kill us both?" he shouts. "Dispel it or else—"
Her voice comes through muffled and desperate. "I'm trying!"
She can't control it? Does she expect him to believe that? He looks down at Soul Eater, considering his tactical options. Force doesn't work—just seems to strengthen it like a reflex. The inverse might stand to reason.
He recalls a spell he rarely needs. Touching his fingertips to the curved surface of his barrier, he casts Cure.
The aura flickers once and then turns dim and glassy. One more cast and it flickers and dies. Riku fires off a decisive Dark Firaga at its user. Kairi collapses into an unmoving heap. The remnants of her aura vanish.
Riku keeps his guard up, waiting to see if she has any other tricks. But this time, she truly seems to have run out of steam. He nudges her shoulder with his boot. She's out cold. Breathing shallowly. Mostly in one piece, at least enough to dump her at Master Xehanort's feet and forget about it.
He hauls her over his shoulder, but pauses when he feels how clammy she is. She might not make it all the way back to base alive with how much blood she's losing. He begrudgingly shifts her into his arms to avoid agitating her wounds.
The feeling of her body cradled against his chest jolts him. It's an agonizing approximation of an embrace. Why does he feel… sad? Nostalgic? Comforted?
A glitch in his own programming. It has to be.
Or a despicable defensive ploy. The same ploy that made him believe for a moment earlier that she might come with him willingly. That she might have been something other than his mark.
He taps into the shard of Xehanort in his chest and invites himself back into the Keyblade Graveyard. The Corridor begins to form a new doorway in its mists.
Images swirl in the mists: a scarred desert valley. Keyblade hilts protrude from the ground like gravestones, stretching out towards impossibly tall, sheer cliff faces on all sides. They cloak the rocky ground in shadow despite the shimmering heat. Chains and shackles hang broken from the cliffs on either side, swinging and clattering limply in the wind. Rough, dry wind buffets him as the doorway begins to solidify through a growing aperture.
A sharp pain in his back forces him forward. He cries out. Kairi rolls out of his arms. The path to the Keyblade Graveyard dissipates. Riku looks down to see the teeth of her keyblade jutting through his chest. Its cheery glow illuminates the wound punching him through. He staggers back.
In rage, he grips the blade, squeezing with fists full of dark energy. It rattles and flickers, screaming before it finally disappears.
He collapses to one knee, muscles spasming in his chest. The hole through the middle of his torso begins to fill up with blood and liquid darkness. He feels Master Xehanort's presence press at the edges of his mind, sensing his sudden mistake. Riku's grimace deepens. The Master will no doubt be disappointed. Kairi should have been his easiest mission.
Riku is the New Organization's youngest because he's far better at killing than the others. Except the Master's other selves, at least. And he'll be stronger than even Terra-Xehanort long before he's that old. Without cheap tactics like stealing someone else's body.
Master Xehanort should know that. So why does he feel no different here than in Castle Oblivion? Why he still have to fight for the Master's respect?
Just out of arm's reach, Kairi stirs. She reaches out. Her fingers spark with a green Curaga spell. It fizzles out.
"Save it," he wheezes. "I don't need it. You missed my heart."
"Are you a Nobody?" she whispers.
He chuckles, then doubles over for a moment as the darkness seeps further into the crevices of his wound, healing him painfully. "Too bad you missed the Master's heart, too." He rises to his knees, looking down on her. She's staring at him again like he's someone he isn't. He sways there, feeling all reason drain out of him. "Want to know what I think?"
He brings Soul Eater down and stabs her down through the chest. He twists viciously, relishing in her wide-eyed nothing stare and mute scream. Inside her chest comes the sound of cracking, crunching glass. There. A wound to match his.
He tries to lean down to her ear, but can't quite get there with his destroyed body. "I don't think Xehanort should have you after all."
He twists again as he pulls out, and with Soul Eater's blade comes her heart in a flood of light.