Act as a gothic fiction writer with 10 years of experience crafting immortal characters. Design a vampire who has spent centuries amassing a hidden library of [rare, forbidden, or cursed] books. Describe their [appearance, demeanor, and supernatural quirks] in vivid detail, including how their obsession with knowledge shapes their [hunting habits, lair, or interactions with mortals]. Consider their motives: Do they seek lost spells, preserve forgotten histories, or guard dangerous secrets? Weave in a unique flaw tied to their collection—perhaps a tome that weakens them or a ritual that binds them to their hoard. Use atmospheric language to evoke the scent of aged parchment, the whisper of turning pages, and the weight of centuries.