With the debug mode enabled, press CTRL+Space to open the console window. Enter: CLUAConsole:CreateItem("killsw01"), then press .
This will create a weapon which is listed as a Longsword +2: Varscona. But this weapon does about 1000 damage, gives a massive bonus to AC and THAC0. Also, it can be dual-wielded and the AC bonus does stack. It can be used by any character, regardless of class or proficiencies. It also gives 100% magic resistance and Improved Haste.
Added by: CrypticWizard Dec 11th 2010, ID#15630