The mansion's marble halls echoed with an unfamiliar symphony - the whine of a chainsaw mixed with... giggles? Ririi materialized from the shadows, drawn by the scent of prey. But something was different. The air carried notes of gasoline and... bubblegum?

  "Big sis! Big sis! Watch this trick!"

  Ririi froze. That voice...

  [CRASH]

  A body flew past, followed by a blur of pink and yellow. Through the crimson mist emerged Lia - her half-pink, half-yellow hair whipping wild, heterochromatic eyes gleaming with unhinged joy. Her oversized pink hoodie and striped thigh-high socks wore an abstract painting of arterial spray.

  "Surprise!" Lia beamed while cutting through three guards in one swing, their screams harmonizing with her chainsaw's song. Blood arced through the air like a crimson rainbow as she pirouetted through her work. "I thought I'd try your hobby!"

  "I... you... WHAT?!" Ririi, terror of the void, master of psychological warfare, reduced to confused sputtering.

  "Nobody hurts kids!" Lia's sing-song voice carried through halls as she skipped through the carnage, chainsaw carving elegant patterns through flesh and bone. Two more guards fell as she twirled past, their bodies hitting the floor in perfect rhythm. "Bad people get the chainsaw! Isn't it pretty? I named it 'Mr. Buzzy'!"

  Ririi watched, shadows writhing uncertainly, as their sweet baby sister turned the mansion into a rainbow-tinted hell. Lia danced through the growing collection of bodies, occasionally pausing to arrange them in artistic poses.

  "Look, look!" Lia twirled, chainsaw slicing through another cluster of guards. Their screams cut off in perfect harmony as she separated heads from shoulders. "I'm doing the thing! The scary thing! Am I scary?"

  "YOU'RE SUPPOSED TO BE THE INNOCENT ONE!"

  "Oh! Want to see what happens when you mix gasoline and glitter?"

  "GLITTER?!"

  [BOOM]

  The crime lord crawled from the technicolor wreckage, trailing sparkling crimson. His bodyguards y scattered around him in glittering pieces.

  "Aww, trying to escape?" She tilted her head, bringing the chainsaw down in a graceful arc. "But we're just getting to the fun part!"

  Bodies decorated the floor like macabre confetti, some still twitching as Lia skipped between them, adding artistic flourishes with her chainsaw. She hummed a cheerful tune as she worked, occasionally stopping to adjust the bow in her hair.

  "Remember when you taught me about pressure points?" Lia demonstrated enthusiastically on a guard, his body crumpling like paper before she finished him with Mr. Buzzy. "I found SOOO many new ones!"

  "HOW ARE YOU SO GOOD AT THIS?!"

  "I know, right?!" Lia hugged her blood-soaked chainsaw, surrounded by her night's work. "Who knew murder could be so much FUN!"

  As dawn approached, the mansion burned in technicolor fmes. Lia sat atop her masterpiece of mayhem, swinging pink and yellow socked feet. The fire cast rainbow shadows through the glitter-infused blood coating the walls.

  "Did I do good?" She beamed at Ririi. "I wanted to make you proud!"

  "I... but... HOW?! You... you used to cry when I killed spiders..."

  "Still do!" Lia chirped. "Spiders are friends! Bad people though..." She revs chainsaw lovingly. "They make such pretty colors inside!"

  Walking away from the kaleidoscope inferno, Lia's feet leaving glittery red footprints, she tugged at Ririi's sleeve. "Can we get ice cream? Mr. Buzzy likes strawberry!"

  "ICE CREAM?! AT A TIME LIKE THIS?!"

  And somewhere in the void, ancient horrors whispered about the shadow beast's crisis - watching their carefully cultivated terror unravel before a hurricane in pink and yellow socks, who turned cosmic horror into a sugar rush without missing a beat.

  Ririi would spend weeks trying to process this, while Lia continued decorating Mr. Buzzy with glitter stickers, occasionally humming the tune she'd choreographed her massacre to.