Korasi's Sword is a weapon obtained as a reward from The Void Stares Back quest, provided you are enough of an idiot to sit through that shit for 2 hours, unless you are doing it for criticism, review or guidance purposes, which in that case you are just plain unlucky. It plays some part in the quest, mainly being used as a lackluster weapon to stop the quest's boss fucking you up on occasion with its 'Disrupt' special attack, but other that than its a spatula covered in red masking tape.
CCTV photo explaing why Jagex reliesed the sword
Using Korasi's Sword[]
Statwise, its pretty much Copy+Paste from the Dragon Longsword, with +60 Stab, +70 Slash and +70 Strength bonus. Its also one-handed, which means its pretty much superior to the Dragon Scimitar, which is handy because those tacky Korean weapons don't have much durability, a bit like Statius' shitty equipment really, although they're more closely related to the Lamb Shanks which Gordon Ramsay refers to as "shit in a plastic bag" (Get on with it. - Angels) Its special attack isn't just a fancy prop for the Void quest, it can also be used everywhere else, where its still the same old shitty lightning effect, but can also hit MULTIPLE ENEMIES! (but only against the pests in The Void Stares Back.)
When the Pkers learned that the special attack doesn't miss, and that it can deal anything from 50% to 150% of your max hit, they immediately began the routine screaming of "OMFG EPIC NEW SPEC WEAPON!" until they realised that the weapon has a 250k alch value. That meant it kept over the Abyssal Whip, Chaotic Maul, Amulet of Fury, etc. This caused a Max Power Forum Shitstorm that even rivalled the time that the Skillers realised a yew tree had been moved one square further north of the Gnome Stronghold bank, and created a gigantic riot. Jagex immediately realised their mistake and duly reduced the alchemy value of Korasi's Sword.
Eventually, Korasi's Sword became popular again, and is now used as fully intended - to place pancakes from the frying pan onto a plate for human consumption.