Gorribal (the Dark Seether) is a sword that was forged from one of the two Shatterbound fragments of Gorshalach. Wielded by Sargeras, this weapon embodies the darkness that exists in all beings, even noble ones. If this weapon is ever combined with the other fragment, which has been reforged into Taeshalach, then Gorshalach will be reborn, although this can only be done by a non-evil being.
In the many years since the shattering of Gorshalach, Gorribal has claimed the lives of many thousands, if not millions of different creatures across the worlds. The most notable of these is Broxigar the Red, an orc that was sent back in time to The War of the Ancients. At the end of the war, he jumped through the portal to the nether where he battled, and defeated, the might of the Burning Legion forcing Sargeras to slay him, but not before Broxigar had managed to wound his leg.
It is unknown what happened to Gorribal when Sargeras was cast back into the nether by the Sundering.