Every cool kid has a Quantum Katana made of...uhh...diamond-coated tungsten...with an edge made of...uhhh...Anti-matter...
Does 10d12 Force damage, critical 1-20/x10, and the target must succeed a fortitude save (DC 10 x damage dealt), or die. If they succeed, they take the cube of the base damage...
But anyway, a normal katana is a masterwork bastard sword.
Oh, by the way, the Quantum Katana, in the hands of a character with 22 strength, does a maximum of 2,001,636,000 damage if the target somehow succeeds the fortitude save (DC 12,600). Minimum of 4,112 if they succeed the minimum DC of 160.