|image swiped from here|
In the Age Of Darkness, Tolivar was the mightiest of the vampire warlords, leading his army of undead across the Starlight Empire, razing towns and cities as they went, drinking the blood of the innocent to fuel their unnatural passions.
As they approached the city walls of the gleaming capitol, the Last Empress ordered her mage council to forge the ultimate weapon and thus was created "Tolivar's Bane"...
... or so the legend goes anyway. The Starlight Empire has long passed into myth as some long-forgotten Western realm, however Tolivar's Bane is still regarded as one of the unique, Legendary Treasures of Tekralh (along with The Mindsword, The Sword Of Unicorn, The Bow Of Kronos etc).
A recurve shortsword - total length 26.5", blade length 19.5", weight: 2lb 7oz - the weapon is enchanted for use against the undead and counts as +6 (to hit/damage) against vampires, +4 against other undead and +2 against everyone else. As a shortsword, its base damage is 1d6.
However, against all undead, a natural roll of an unmodified 20 to hit causes instant decapitation (although powerful vampires and liches can save versus magic to avoid this effect and instead simply take double damage).
The sword gives off a faint glow - not enough to see by - if undead creatures are within 120ft, even if shielded behind stone walls.
The final known power of Tolivar's Bane is its ability, while drawn, to grant its wielder the power to 'turn undead' as a cleric of equal level to the wielder's (Swords & Wizardry, Complete Rulebook edition, page 42/43) - even in campaign worlds where clerics don't exist (such as Crypts & Things, which I intend to use for next year's Tekralh campaign).
Background Information: Tolivar's Bane was original designed as an ersatz version of the sword used in Lesbian Vampire Killers (as that was too much of a jokey-weapon to translate comfortably into a semi-serious game world) but also, the more I thought about it, taking on certain qualities of Buffy's magical "slayer's axe" from the final season of the TV show.