Stormbringer is a sentient sword of immense evil power from Michael Moorcock's Eternal Champion series. The sword is most known for being wielded by the Eternal Champion, Elric of Melnibone , and his ancestors. The sword is capable of sucking out the souls of those it kills, and bestowing energy to its wielder. This is quite helpful to Elric, since he is a frail wizard, previously only kept alive through constant consumption of drugs and potions. Wielders of Stormbringer must constantly resist urges to kill, so that the sword may feed.
Stormbringer has a "brother sword" of similar power called Mournblade. Mournblade was wielded by Elric's cousin Yyrkoon.
Elric found Stormbringer in a organic cavern in a shadowy dimension while he was chasing Yyrkoon, who escaped in the cavern to take both Stormbringer and Mournblade.
After a duel with Yyrkoon, Elric decided to bring Stormbringer with him in his journey since it gave him necessary strength even without the use of his potions. Throughtout the series, Stormbringer tended to slip out of Elric's control and kill his allies and loved ones, including Cymoril, Rackir, Moonglum and Zarozinia.
Despite all the torment it put Elric through, Stormbringer kills Elric, gains a demonic form and tells the dying Elric that it was a thousand times more evil than him before flying away unpunished in the new world created by Elric's sacrifice.
It is unknown what Stormbringer did after the events of the Elric saga.
- Stormbringer is the possible inspiration for many weapons and artifact in fantasy books, comics and videogames, including the Black Sword from Ultima 7, the Soul Reaver from Legacy of Kain, Soul Edge and Frostmourne from Warcraft 3. All of these items are mystical swords with the power of absorbing souls.