Iccel (3.5e Equipment)
From D&D Wiki
This blade looks like a longsword except it has a toothed edge and a curve, it is heavy, but easy to hold even by one hand. It is a bit harder than an ordinary longsword, though, and deals more damage than it. Also, most fighters find it hard to use such a weapon in combat, so special training is needed (the appropriate Exotic Weapon Proficiency feat).