Archive of Our Own ^beta

Chapter Text

Giyuu can’t believe it.

After so many years of trying to rid Muzan and demons from the world, they’ve finally done it. This should be cause for celebration.

Instead, all he feels is despair.

Fighting Muzan cost him his precious omega. The only person he’d given his heart to. The largest loss since Sabito. Losing Sabito was scarring, life-altering, but a reason to continue the fight. Losing Tanjiro made it all seem pointless.

He hadn’t grown at all since losing Sabito. He was still that weak child, unable to protect the people worth more than the world to him.

Giyuu kneels in front of Tanjiro’s motionless body and grasps his hand tightly within his own, “I’m so sorry Tanjiro. I’ve failed to protect you. I’m so sorry,” he sobs, “I’m sorry Nezuko. I wasn’t strong enough to protect him.”

Tanjiro’s soft amber scent suddenly changes, and Giyuu’s head snaps up in response. What is this putrid smell? It smells like a burning building, blood, and gore.

He watches in shock as Tanjiro lifts his head to the sky. “Tanjiro?” he softly calls. The air around them turns even more acrid, strong with a sudden violent curl. Giyuu lunges at the closest Kakushi, screaming, “Watch out! Get away from Tanjiro!” seconds before his omega reaches out with sharpened nails, intending to maim flesh.

The Kakushi grunts with Giyuu’s full weight colliding into him, pushing him into the ground.

The other Kakushi surrounding Tanjiro look at Giyuu in confusion before turning their eyes onto Tanjiro. They watch as he quickly lunges towards another Kakushi, before lurching back, screaming in pain.

“Tanjiro!” they shout, frantic, moving to help him.

“Get back! Get away from him!” Giyuu grunts, scrambling upright.

“But he’s hurt!” One shouts, before watching in horror as Tanjiro’s face begins to burn, steam rolling off the boy in waves.

Tanjiro screams and wails in pain, clutching his burning face. His eyes dart around, before settling on the shade of a nearby building. He rises to his feet before making a quick dash towards the sanctuary.

“Get back! He’s become a demon!” Giyuu yells before launching himself at his omega, “Anyone capable of holding a sword, get over here quick! Tanjiro’s become a demon! Keep him out of the shade, burn him while he’s still weak!”

Giyuu holds back a sob as his body collides with Tanjiro’s, pushing him into the ground. His alpha screams at him to fix their omega’s pain, to bring him relief. He struggles with Tanjiro for a moment, before, to his horror, his face stops burning and begins to heal. Shit, he’s already resistant to the sun? It’s not all that surprising, considering Tanjiro’s strong will, and his genetic connection to the sole other demon in history that resisted the sun.

Momentarily lost in thought, Giyuu feels Tanjiro’s body seize before he throws Giyuu’s body off his own. The omega quickly stands upright, growling at the alpha in front of him.

Giyuu’s heart clenches as he meets his omega’s eyes, no sign of recognition within those now pink irises.

First his omega seemingly dies, then he’s reborn as a demon. Now, he has to fight his darling, with no idea how to end his life. Giyuu frantically recalls information about Muzan, any hint of a weakness he can exploit. Muzan couldn’t be killed by decapitation, only exposure to sunlight. With Tanjiro immune to the sun, is there even a way to kill him? His heart aches at the thought of hurting his omega, but is this even his omega anymore? He smells almost entirely different, doesn't seem to recognize him, and tried to kill their comrades. Tanjiro deeply values the corps members, there's no way his omega would be able to cause significant harm to one of them not threatening his loved ones.

Giyuu barely has a moment to despair before Tanjiro’s growl crescendos and he launches his body at Giyuu, nails aimed at his throat. Giyuu clenches his sword tighter, body aching with his numerous injuries, and hesitates to swing his sword. His beloved omega, his darling Tanjiro. He can’t do it, he can’t swing his sword. Giyuu whispers, “I’m sorry, Tanjiro,” before closing his eyes and allowing his arms to fall.

Giyuu opens his eyes when he hears a thud and yelling. During his surrender, Inosuke has gotten between them, and is yelling at his omega. His alpha immediately bristles, how dare he raise his voice and sword to his omega? He attempts to squash the rage flooding his blood. He takes a second to recompose himself, arguing with his alpha. They need to put Tanjiro down before he’s completely gone, end his misery before it truly begins.

The smell of blood hits his nose, his head snapping up at the scent. He’s shocked to see Nezuko has appeared in the confrontation during his moment of distraction, attempting to console Tanjiro. He barely has time to scream at them to fall back, before Tanjiro sinks his teeth into his sister’s shoulder.

There it goes, Giyuu’s last hope at saving his precious Tanjiro. He’s tasted blood, he’ll go into a frenzy and slaughter everyone around him. His heart and alpha cry in despair and grief. How much more is he expected to take? He’s lost countless friends and comrades in the fight against Muzan. Now, he’s lost his other half.

His other half will be the one to take the rest of his comrades, including his sister-in-law.

Chapter Text

Giyuu wants to scream along with Tanjiro. He can feel his bond overflowing with various emotions, swirling and mixing with his own. He, too, feels rage, grief, fear, and sadness. But, the bloodlust is not his own.

He can’t help the tears streaming down his face at Tanjiro’s scream. He can only watch on in immense pain, mentally, physically, and emotionally, as Tanjiro struggles in the grasp of his friends.

The rage he feels when Tanjrio’s friends begin to hit him does nothing to soothe the other emotions. He hardly feels the spike of emotion struggling through the others.

As the boy drops to the ground over Nezuko, brandishing Muzan’s bone appendages, the rage and grief battle for the strongest emotion. How dare that filthy Muzan bastard taint his omega. His strong, beautiful, precious Tanjiro. With a scent as warm as sunlight, a will to protect his loved ones, and a desire to end and prevent tragedies and suffering. How could that bastard continue to make the sweetest omega known to earth suffer even more after destroying his entire family, killing his friends and comrades, and attempting to absorb his only remaining blood.

Giyuu’s blood boils the more his thoughts continue.

Giyuu attempts to shrug these thoughts off, launching into action to protect Tanjiro’s friends from himself, “Water breathing fourth form, Striking Tide!”

His sword clashes heavily with Muzan’s-no, Tanjiro’s bony appendages, narrowly changing their trajectory. He begins to panic, Tanjiro hadn’t attacked any of his friends prior to biting Nezuko, just tried to get them off him. But now, he fears with the newly acquired taste for blood, there will be more death and bloodshed on this battlefield.

As he continues to fend off attack after attack from his omega, it dawns on him that Nezuko has not been moved or harmed since he’d taken her to the ground. He narrows his eyes slightly at the blood coating the boy’s newly sharpened teeth, before searching those unfamiliar, yet familiar, eyes.

“Are you fighting him too, Tanjiro?” he whispers in surprise. Nezuko has been actively bleeding right under him, an easy meal to access even during battle. Yet, he’s made no more to harm the girl. Maybe his Tanjiro is still in there, desperately fighting to return to them.

Hope blooms within his very soul, “Tanjiro! Baby, please come back to us!”

He grits his teeth as he’s met with nothing but growls and snarls before attempting again, “My sweet omega, please. We’re here for you! You can fight this!”

Giyuu had repeatedly been told he’s not good with words, especially ones of comfort and encouragement. But, he can’t help but try. For his omega, he’d try anything. Nothing would be too much effort to help the sweet sunshine boy.

“My love,” he begins to plead, continuing to fend off attacks, voice warbling slightly, “Nezuko and I are here, fighting for you. Fight for us! Don’t make us cry. Please…”

He struggles to hold in a sob, before he realizes the attacks are decreasing in strength and speed. He narrows his eyes and rakes them across Tanjiro’s figure.

Tanjiro’s boney appendages slowly come to a stop, hovering around him, twitching with slight aggression. The boy stands, mouth forming a snarl, as he stares at the alpha.

Giyuu tenses as he watches the boy sniff the air before his face relaxes marginally.

“Tanjiro?”

Tanjiro’s body twitches as the call. The stench in the air lessens before that warm, slightly sweet aroma of amber begins to return.

Giyuu’s eyes widen, heart pounding as the scent begins to wash over him. He takes hesitant steps towards the boy, pausing when Tanjiro tenses. When the boy relaxes, he resumes his steps, hand still tightly gripping his sword. “Baby?” he questions.

The omega tilts his head at the questioning tone, before his eyes roll back into his head and he abruptly slumps. The bony appendages quickly return to the boy’s body, seeming as if they were never there to begin with.

Giyuu rushes forward, narrowly catching the boy before he plummets to the ground. He swipes the omega’s bangs off his forehead and cradles his face in one hand, “Baby? Can you hear me?”

After a moment of silence, Giyuu begins to panic. He calls out to the others, “Quick, get over here!”

Giyuu lays his wrist against the boy’s scent gland, rubbing his scent into the delicate skin, before looking towards the young swordsmen and Nezuko, “Spread out your pheromones. Not too strong, but make them apparent.”

The others nod before doing as they are told.

They watch in silence as Tanjiro’s body remains nearly still. They would believe him dead, were it not for the slight rise and fall of his chest.

“He’s fighting him, isn’t he?” one of the boys asks.

Giyuu nods, but Nezuko is the one to answer, “Yes, he has to be.”

Giyuu can only hope to have his darling return to him. He has faith, though. If anyone can defeat Muzan in a psychological battle, it’s his omega. He believes in his will-power, his strength, his love for him and his friends, and their bond.