Elric of Melniboné
Michael Moorcock created a sinister magic sword in "Stormbringer", wielded by Elric of Melniboné. This black sword has the power to suck out the souls of its victims and transfer their energy to its holder. It also appears to have a mind of its own, sometimes striking against its "master's" will. Mercedes Lackey's creation, the sword Need is similarly independent, although along less sinister lines.