The Eminence of a True Monarch of the Shadows

[Third Person's PoV] 

"You my dear sister, are the Goddess of The Sword and Black Lightning, The Reaper of the Shadows, The Monarch Slayer, She Who Draws Her Blade for Death, The Incestuous Bro-Con, Death's Eternal Sister, and The Bride of Shadow and Death" 

"Incestuous Bro-Con!?" Claire exclaimed, taken aback, "I'm not a bro-con!" 

"That's the part that you deny?" Cid asked, looking at her weirdly. 

Claire blushed slightly as she pouted, she was pressing her fingers together as she muttered, "Well I won't deny that we've done some… Stuff… But a Bro-Con?" 

Cid spread his arms wide, tilting his head back with a mischievous grin as he closed his eyes. "Just tell me you love me~," he teased, his voice lilting.

"LOVE THIS, YOU BASTARD!" Claire shouted, her face burning bright red. With a burst of energy, she launched herself at him, delivering a perfectly executed dropkick to his chest.

The impact sent Cid staggering a step back, yet he barely flinched. He brushed the front of his shirt as if removing a speck of dust, his expression completely unbothered. Meanwhile, Claire landed gracefully, flipping in the air before brushing her hair back with an exaggerated flourish. Her smug smile faded when she noticed Cid staring at her with a calm, straight-faced expression.

"Now, come on," she said, her irritation quickly replaced by a cheerful grin. "It's time for that sibling bonding time you promised."

Cid scoffed lightly as he fell in step beside her. "Funny how the same person complaining about the titles seems to enjoying them."

Claire scratched her cheek sheepishly, letting out a small chuckle. "Alright, I admit it. I kind of like the titles. 'She Who Draws Her Blade for Death' has a certain gravitas, even if it's long. And 'Death's Eternal Sister'? That one's my favorite."

Cid allowed a faint smile to touch his lips, his hand instinctively reaching out to ruffle her hair. The gesture was brief but filled with brotherly affection. Without another word, he teleported them out of the void and back into the world above.

They reappeared in a vast open field under a golden sky. Claire blinked, taking in the serene surroundings before glancing at Cid with a wary look. "Shouldn't I practice with these powers a bit before diving into the fight against the big boss?"

Cid waved dismissively. "You'll get plenty of practice inside. He's holed up on the top floor of his little fortress, so we'll have to climb our way up."

"Ah, I see," Claire said, her tone shifting to excitement. "We're going to fight his minions first. Perfect!"

Cid unsheathed his ebony sword, its blade radiating a dark, ominous aura. The air around them seemed to grow heavier as he sliced through the fabric of reality itself, tearing open an entrance to a hidden dimension. The cut rippled like curtains of liquid shadow, and Cid casually pulled them aside, revealing a fiery realm within.

He gestured grandly toward the portal. "As they say, ladies first."

Claire curtsied dramatically, holding the hem of her skirt. "Why, thank you, good sir," she teased before stepping through.

Cid followed, shaking his head with a chuckle. The dimensional rift sealed shut behind them, leaving the field empty once more.

Inside, Claire's eyes widened as she took in the scene. They stood amidst the ruins of a once-great city, the crumbled buildings now engulfed in roaring flames. The air was thick with ash and the distant sound of agonized wails. Towering over the desolation was an enormous infernal castle, its spires piercing the blood-red sky like jagged teeth.

Her gaze landed on a monstrous figure lying before the castle gates—a colossal, three-headed dog resting atop the scorched earth. "Is that… Cerberus?!" she exclaimed, her voice filled with awe.

The beast stirred at the sound, its three heads rising in unison. Their ears twitched as their glowing eyes locked onto the intruders. A low, menacing growl rumbled from their throats, and flames flickered between their snarling teeth.

Claire's eyes lit up with excitement. "Can we keep him?" she asked, turning to Cid with a hopeful grin.

Cid blinked, looking at her as if she'd just grown another head. "What?"

"I mean, just look at him! He's so cute!" Claire cooed, switching to a baby voice as she took a tentative step toward the beast.

Cerberus responded with a deafening roar, all three heads inhaling deeply before spewing a torrent of blazing fire directly at her.

Claire sighed as the flames roared toward her in slow motion. "Okay, never mind," she muttered, extending her hand. A ripple of dark slime coalesced into a blade, nearly identical to Cid's but encased in an ornate scabbard. Her eyes sparked with black lightning as she thumbed the hilt, releasing it with a satisfying click.

In an instant, she disappeared, leaving a streak of black lightning in her wake. She weaved around Cerberus, her movements too fast for the creature to follow. Moments later, she reappeared in her original spot, sheathing her blade with a sharp snap.

All three of Cerberus's heads slid cleanly from their necks. The massive body collapsed in neat, symmetrical pieces as though sliced by an impossibly sharp knife.

Cid raised an eyebrow. "I've been meaning to ask. Why is your lightning black?"

Claire shrugged as she crouched to inspect the remains. "Your blood. I infused my power with it. Turns out, it works wonders."

She picked up a thick collar from one of the severed necks. As she held it, the oversized object shrank to fit neatly in her hands. A mischievous grin spread across her face as she wrapped the spiked collar around her neck.

She posed dramatically, tilting her head and fluttering her lashes. "Well? How do I look?"

Cid rolled his eyes. "I'd rather not say."

Claire pouted, sticking out her tongue and holding her hands up like paws. "Come on, big brother. You can say it—you own me now."

Cid's lip twitched in irritation. "They should add 'pervert' to your list of titles."

She sighed dramatically, removing the collar. "You're no fun. I guess I'll save it for the bedroom—oh, wait. Is this a key?" She inspected the collar closely. Sure enough, a small, ornate key was embedded in its design.

"What kind of idiot leaves the key to their fortress on their guard dog's collar?" she muttered.

"The arrogant kind," Cid replied. "The kind that doesn't expect anyone to defeat their pet."

Claire pocketed the key and unlocked the massive doors to the infernal castle. As she did, a low growl made her freeze. Turning slowly, she saw a smaller, shadowy version of Cerberus—this one glowing with black and purple energy—sitting patiently with its tongues lolling and tail wagging.

"Since you wanted one so badly," Cid said with a shrug, "I made you your own."

Claire's eyes filled with tears of joy as she tackled him in a hug. "Thank you! Thank you! Thank you!" she cried, peppering his face with kisses. "You're the best brother ever!"

"Please don't say that after kissing me…"

Claire giggled before bounding over to her new companion. "Come here, you big furball!" she shouted, burying her face in its fur.

The shadowy Cerberus let out a happy bark, its tail wagging furiously. Cid crossed his arms, watching the scene with a faint smirk. "You two deserve each other." he teased.