When the stars align for us

Chapter 13

Having already finished off Tamayo, Muzan Kibutsuji strode through the castle, his intentions clear: he wanted to eradicate all demon slayers in the Infinity Castle. Unaware of the poison circulating through his body, the Demon King carelessly made his way across multiple hallways and ignored the constant feeling of fatigue and power loss in his body. As he walked, he began to notice the Castle behaving strangely. He couldn't find his way around anymore.
'Nakime, what the hell are you doing?!' he shouted.
As Yushiro continued to clear the way in favor of the slayers, Muzan became more and more angry at the former's antics. He used his powers to find his pawn, aiming to kill her.
...
'What's going on?' Zenitsu asked fearfully, as the ground started to shake.
'We're about to head out,' Giyuu explained simply.
'Kocho,' he whispered, unnoticeably grasping her forearm, 'I need to talk to you,'
A bit surprised, Shinobu followed him to another corridor. They stopped, Shinobu leaning against the wall, Giyuu facing her.
Giyuu sighed and closed his eyes tight, opening them again. Shinobu crossed her arms.
'Look...we're approaching the final battle,' he began in a low voice, 'There's no way to know if we're both going to make it out alive. So...I just wanted you to know,' he braced himself before grabbing both her hands, '...I love you,'
Shocked, Shinobu was at a loss for words. She simply stared at him, the situation unbelievable to her. She knew she loved him, but she could never have guessed that he felt the same way.
'...I love you too, Tomioka,' she whispered back, smiling, a genuine smile.
Before she could process what had happened, Giyuu kissed her, his hands on her back. After a few seconds, Shinobu broke the kiss, resting her forehead on his, arms now wrapped around each other. Eventually, they came to their senses, remembering that their priority at the moment was the battle, and slowly let go of each other. Shinobu turned around to see Kanao standing wide-eyed at the edge of the corridor, which was dispersing into mist.
'Kanao!' Shinobu ran towards her, 'How long have you been standing there?'
'...Don't worry, I won't say anything,'
Shinobu sighed and hugged her sister, releasing her almost immediately and telling her to unsheathe her blade, doing the same thing herself.
She looked back at Tomioka, who smiled softly upon making eye contact.
...
All the remaining slayers now stood in front of Muzan Kibutsuji, Hashira at the front. The moon shone brightly above them, as the enemy began to attack: it was going to be a long night. All the slayers could do was dodge the attacks until sunrise, and possibly weaken the demon, only for him to regenerate instantly. Muzan was at his strongest-or what he thought was his strongest.
Giyuu and Tanjiro were fighting alongside each other, while Kyojuro, Sanemi, Gyomei and Ayaka all fought independently. Muichiro had been carried away by the kakushi squads, no longer being in a condition to fight. Mitsuri and Obanai also fought together, the latter doing his best to protect the former, while Shinobu easily dodged incoming attacks on the far right of the line, using her speed. Shinobu, however, had a burden upon her: Kanao. She had to protect her younger sister, who would continuously slip out of her grasp and aim for the demon. Shinobu covered the girl with her own body: she would do anything to keep her sister alive.
Sanemi, meanwhile, had the exact same problem with Genya.
'Nee-san,' Kanao suddenly spoke, 'I need you to let me fight,'
'No, absolutely not. I let you fight the Upper Rank, but I'm not letting you go unprotected against this piece of-'
'Nee-san, I thought you said I was a good fighter,'
'You are, but not even we stand a chance against him!'
'Nee-san, I know you're afraid that I'll die the same way Kanae nee-san did. But I need you to trust me,'
Shinobu closed her eyes tight and sighed.
'Fine, but be careful!'
Kanao smiled.
After a few hours, Shinobu noticed Obanai dragging Mitsuri out of the fight. Noticing their wounds, she decided they needed help. Shinobu glanced at Kanao and made up her mind.
'Kanao, can you manage without me for a few minutes?'
'Of course, nee-san!' she smiled.
Shinobu couldn't help but smile back, before heading towards the injured Hashira.
Meanwhile, Genya managed to convince Sanemi that he could take care of himself, before his brother finally allowed him to take part in the battle.
'Iguro. Iguro, please listen to me!' Mitsuri began, crying her eyes out.
'Yes, Mitsuri?'
'Iguro, can you promise me, that if we make it out of this, you will make me your bride? And that if we don't, but we're reborn as humans, you will do so in another life?'
Now Iguro's eyes began to let out a stream of tears.
'Of course, if you will have me. And I promise, I will protect you,'
As the pair continued to cry even harder, Shinobu finished with them, calling for the kakushi to take them to the Butterfly Mansion.
She hugged her best friend before allowing the squad to take her.
'Kocho, are you alright?' Giyuu asked from the front line, apparently not caring about the confused stares he received.
'Fine,' she smiled, 'you?'
'Same,'
Shinobu seemed to have forgotten where she was, until she snapped back to reality, grabbing the hilt of her blade and rushing back into the battle.
I can't believe I put the confession in Chapter 13, but it's not like I had a choice.