Korasi's sword is a weapon obtained from the quest The Void Stares Back. The sword is the personal weapon of Commander Korasi, and is used to defeat the Pest Queen at the conclusion of The Void Stares Back.
The Void Stares Back requires 80 Magic and 78 Attack and Strength as well as other skill requirements, which effectively act as minimum requirements to wield the sword.
After the quest it can be re-purchased from Commodore Tyr for 500,000 coins. When lost upon death to another player in the Wilderness, the sword turns into 245,000 coins. If killed by a monster, the sword simply drops and may be picked up. You can not purchase a second Korasi's sword if you already own one, but Commodore Tyr will sell a replacement if you have an augmented Korasi's sword.
Korasi's sword has a special attack called Disrupt, which consumes 60% adrenaline. It deals up to 300% weapon damage as magic damage, which also hits any foe adjacent to the player. The special attack makes the sword very powerful, as it can hit with very close to the same power as Ultimate abilities like Overpower without requiring a full adrenaline bar.
Use of this special attack converts some of the experience from the death of the target into Magic-style experience, as determined by the combat settings of the player: Magic, Defence, or Magic and Defence. Therefore a player can expect slightly less than normal experience going towards a melee combat skill they are training unless they've chosen to only receive Defence experience from magical combat.
Champions in the Conquest activity seem to hold a sword similar to Korasi's sword, only bigger and broader.
Wielding this together with an active aura will cause a graphical glitch in the Equipment Stats. Additionally, the outline of an aura will not match the sword.
The sword received a buff on 7 January 2014, raising its stats from level 68 to 75.
The sword used during the quest or Dominion Tower has level 70 stats (856 damage and 1486 accuracy) and never has the critical bonus. Also, this version of the sword is required to defeat the Pest Queen in the tower, even if the player brought their own. Both will damage her, but only the supplied version's special attack will work to disable the Queen's own special attack.
The sword used to be a slashing weapon but was changed to a stabbing weapon. The quest version remained a slashing weapon.
On 17 March 2014, the sword was reverted from stab to slash again so that is overridden by scimitars and longswords instead of daggers and rapiers as it was before the Evolution of Combat.
On 7 April 2014, it was reverted back to a stabbing weapon, but its slashing animations are kept so it is still overridden by longswords and scimitars.
The sword's special attack counts as a fire-type attack while fighting the Dagannoth Mother.
It is possible for the special attack to miss (like with a regular attack). It rolls to attack twice if able, allowing you to miss either or even both attacks. Taking into account that it is also indiscriminate as to what it targets as secondary (anything technically attackable within 1 game space). This can lead to the special behaving inconsistently.