"I'LL KILL YOU!" Shizuo roars, eyes struggling to stay locked on his rapidly moving target. Izaya shouldn't be so hard to track in this mostly empty warehouse, but of course he somehow is. Shizuo catches a flash of movement to his left, gleaming eyes and stupid fur coat, and his body turns on instinct, throwing a fist out and crashing into a large support pillar. The building groans in protest, but he ignores it in favor of continuing the hunt.
"Too slow!" Izaya laughs, somewhere to his right now and heading further into the building. He follows, footsteps echoing like thunder in the mostly open space, save for some discarded boxes and support beams. Izaya cuts around sharply around another thick pillar, and in his haste to follow he slams into it on his way past. It cracks, concrete crumbling where his shoulder has left a decent crater.
His blood is thrumming, heart pounding every time he catches a glimpse of mocking red eyes. No matter how close he gets, every punch he throws catches old wood or concrete, and no matter how loud he roars, his opponent wears the same exhilarated grin. He clearly finds Shizuo's violence and loss of control charming, and Shizuo hates him more for it.
Izaya ducks under his arm, laughing when he ends up with his fist embedded in one of the walls. He rips it free, looking 'round for anything he could throw at the pest. Izaya practically reads his mind, getting up in his space with his hands behind his back and a smirk on his face.
"Too bad, huh? There's nothing here to throw! But I," He pauses here to bring forth a knife, and Shizuo has to duck his head back to avoid being slashed across the eyes. "I have these." He taunts, skipping back and away from Shizuo fast as ever.
"You little fucker." He pants, pausing when he notices a pillar in the center of the room. It's thicker than the others, tall and almost intimidating. He doesn't think about it, he can't in his anger, his feet are moving with ideas of improving his range greatly. He reaches it quickly, hands gripping what they can, and he starts to pull.
There's a sharp intake of breath behind him, Izaya no doubt, though he can hardly hear over the buildings sudden shaking and groaning. It cracks in several places, most importantly near the top where it connects with the rest of the ceiling's structure, and makes an awful grind as the whole roof starts to shake and creak.
"Wait, Shizu-chan!" Izaya yells, panic ringing out in his voice but it's clearly too late. A chunk of debris falls, clipping Shizuo's shoulder as if the building itself is seeking revenge. He lets go of the pillar, stepping back slowly, eyes wide and staring up as the pillar starts to tilt and the roof begins to crumble.
He's snapped out of it when Izaya loops an arm around his own, yanking him out of his thoughts and getting him to move. They rush towards the door as more and more of the building starts to collapse around them, and the informant lets go of his arm so they can both move easier.
Izaya is faster, closer to the door when he's struck by a thick clutter of metal and heavy wood crashing down from above. It strikes the back of his head with enough force to snap his neck and break his skull at the very least. Izaya hits the ground, going completely limp in the almost instantaneous grip of death.
Shizuo is paralyzed. Time slows around him as he stares at the body. Just like that his life is gone and stolen by Shizuo's mistake, red eyes dead and staring straight ahead with no light. His ears ring with the symphony of his errors literally crashing around him, body gone numb like Izaya's stolen his ability to move and taken it as a souvenir on his way to the afterlife. He wonders in that moment all the possibilities of his once enemy's resting place. Hell is his first thought, but he doesn't know. Maybe it's nothing. Maybe it's nothing and his soul is just gone and Izaya just no longer exists.
Air rushes behind him, and a small part of his brain supplies that the center beam must finally be falling. He stays where he is, the two seconds it takes for that beam to fall feeling like an eternity. He expects he'll wind up pretty badly injured, possibly unable to walk, and in his shock and unexplained grief he accepts this as a fitting punishment. He stays as still as possible, staring down at the limp body a ways ahead of him and knowing it's his fault.
He doesn't expect it to be enough to kill him.
The beam crashes, along with the rest of the building, and he floats in a haze of pain and the tiring struggle to breathe. Time passes slowly, as he lays in the rubble. He closes his eye for a moment to protect against the falling debris, and when he opens them again the sky is dark and the dust has settled. All he can see of Izaya now is a bloodied hand and a dusty fur sleeve, illuminated by semi distant city lights.
He floats again, pain fading the longer he lies there and the more blood that pools slowly from various wounds on his body. By the time a fireman, or someone of a similar crisis profession, is tugging him out, he's stopped breathing. He tries, thinks of his little brother and dies to draw a breath, but blood bubbles up instead and he can't.
The sight of debris and broken things blur where he lies, and he can't feel the firemen touching him anymore. Worried faces swarm, and the sounds of sirens and a woman mentioning he's not breathing fade away. His eyes are closed by someone; the woman, he thinks, and he lets go.
Warmth sweeps over his body, heating his skin in a pleasant wave. He's lying in the grass, knows this because he can feel the cool touch of their blades against his shoulders, arms, and legs. A breeze sweeps by, rusting his hair and bringing forth a pleasant sigh from parted lips. A deep breath proves the air is crisp and fresh, filling his lungs and head with a wonderfully pure sensation.
He opens his eyes to the sun, and finds staring at it brings no pain or otherwise unpleasant reaction. He marvels the clouds, pure white and fluffier than he remembers ever seeing. It's the picture of perfection and peace, and Shizuo thinks spending eternity here alone is all he could have asked for.
As he stares at the clouds and realizes he's dead, he can't seem to care. Kasuka and everyone else briefly enter his mind, but he can't find it in himself to be upset. He has the overwhelming feeling that everything will be okay, and nothing will bother him ever again.
He's finally gotten the peace he'd longed for all his life. Here, in this small paradise meant just for him, he's finally free. Free to just exist with no worries, distractions, or nuisances-
"Took you long enough." Izaya sighs, face popping into view as he leans over Shizuo. He yells, Izaya jerking out of the way as he quickly sits up.
"Flea?!" He exclaims, taking in the sight of a fairly grumpy Izaya. "What- no! Why are you here?!" He gasps, glancing around his sunny little hill. Save for a dead tree, there's nothing but grass and sunlight stretching around them.
"Welcome to our afterlife, Shizu-chan."