The Daggers of the Crimson Witch

Sentience. The dagger holds the consciousness of the Crimson Witch. All who wield the dagger with ungloved hands hear her voice and must make wisdom saving throws or fall to evil. Wielders learn the Abyssal language upon falling to the dagger's evils.   One Dagger. There are only three of these in existence, and their powers grow when combined with each other. Killing a person with this dagger allows the wielder to shapeshift into that person.   Two Daggers. When two of the three daggers are combined, the wielder gains the ability to cast these spells: Fabricate, Hallucinatory Terrain, Major Image, or Phantasmal Killer. Upon casting these spells from the dagger, they cannot be cast again until the next dusk.   Three Daggers. When all three daggers are combined, the wielder can use an action to become invisible. The wielder will remain invisible until they stop holding the dagger, until they attack or cast a spell that forces a creature to make a saving throw, or until they use a bonus action to become visible again.

During the year 681 AD, Count Krolock, an ancestor of Duke Laurent, and an ancestor of Marquis Fenrir defeated Queen Carmilla in battle. In a last-ditch effort to save herself from permanent death, she created three daggers that hosted her consciousness and spread them throughout the land by other means. Her physical body lays dormant deep beneath the earth while she communicates her will through her daggers.