My Sadistic Sister's Perfect Prison: A Vampire's Escape

Once, Lily adored her elder sister. Now, she's a caged vampire, enduring unimaginable torture. Chained in a hidden dungeon, her potent vampiric regeneration, meant to crush her spirit and enable endless torment, instead forged an unyielding will. Every severed limb, every agonizing cut, only fuels her burning obsession for freedom beyond the castle's suffocating walls. Her elder sister, once a beacon of gentle love, is now a sadistic captor who crafted this 'world' as Lily's perfect, inescapable prison. But an external, cataclysmic attack suddenly shatters the illusion of this contained reality, tearing at the very fabric of her sister’s domain. Lily's endless torment has given her a unique understanding of her prison. Can she seize this chaotic opportunity, weaponizing her very suffering, to not just escape, but tear down the world built by her twisted sister?"