The Blackrazor was one of the magical artifacts you found in the old Advanced Dungeons and Dragons adventure module, White Plume Mountain. From what I understand, it is pretty clearly modeled after Stormbringer, the evil black soulsucking sword in Michael Moorcock's Elric series of novels.
Back when I was playing D&D in junior high, none of us had read the Elric novels and had to borrow modules from the richer players during our lunch breaks, so we didn't know squat about any literary implications of our gaming -- nor did we care! All we knew was that there was something called a Blackrazor that was solid black, wicked sharp, and the merest cut was all it needed to suck someone's soul out, leaving a bubbling pile of protoplasm on the dungeon floor. Up against a Red Dragon? Cut it on its foot, reduce it to protoplasm, grab all the treasure. Pestered by orcs? Slice and dice, reduce 'em to protoplasm, grab all the treasure. Small children in the road? Cut 'em on the arm, reduce 'em to protoplasm, grab all the treasure. (Everyone in our games was loaded down with gold and powerful magic items. It's a requirement for junior high D&Ders.)
Even though it was supposed to be a unique artifact, everyone in the party soon carried one around. Even though magic users weren't supposed to carry swords, ours did anyway -- and almost quit casting spells, so powerful was the lure of the Razor. Even though it was supposed to be a weapon of pure, unadulterated Evil, our supposedly Lawful Good cleric lugged one around -- and smote everything in his path, whether ghoul, moppet, kindly ally, or fluffy bunny. We were underage, hormonal, picked-upon geeks, our veins pulsing with a dangerous mix of testosterone and seminal fluid. We couldn't beat the jocks. We couldn't talk to the cheerleaders. We could just barely impress the teachers. But by God, we could slaughter an army of ogres in six seconds flat, thanks to our bad-ass, solid-black, wicked-sharp, soul-devouring Swords of Infinite Chaotic Evil!
Most of this writeup had nothing to do with the Blackrazor. Sue me for reminiscing.
Oooh, a +20 Editorial War Hammer of Softlink Slaying! Gotta git me one of those...