The Killing Edge (キルソード Kirusōdo, known as the Kill Sword in the Japanese version) is a very lethal weapon that gives the user an increased critical rate from 20-30. Despite there being more powerful weapons in terms of power, the Killing Edge is a sword that many players use even in the final chapter of the game in question. This sword is especially dangerous in the hands of Swordmasters, which can raise their critical hit stat to well over 50. Its only drawback is the fact that it is notorious for having very poor durability throughout the series.
The Killing Edge can also be used as an effective means of training and/or protecting low-level units, like myrmidons and thieves. It requires only C weapon level to use, whereas most weapons of equal or greater power require at least A or S level. The critical hit boost can also help units to deal massive damage or even kill much stronger foes, helping to give them a lot of experience. Its light weight also generally grants units the ability to strike accurately and swiftly. In addition, Assassins wielding a Killing Edge have a higher chance to deal the skill Silencer/Lethality that one-hit KO's the Enemy, regardless of health.
In the games, Killing Edges are often very rare, though still accessible. Myrmidons usually equip them as their starting weapon, and it is the trademark weapon of Jaffar. In his official art, Jaffar is always shown to be dual wielding two Killing Edges specially designed as knives to fit the assassin's animation style.