The Dark One's curse is a curse featured on ABC's Once Upon a Time.
- Nimue - the first Dark One
- Gorgon the Invincible - becomes the Dark One at one stage, resembled a Bandersnatch
- Zoso - became the Dark One after Gorgon the Invincible, was controlled by the Duke
- Emma Swan - became the Dark One when the darkness chose Emma as its next host, until its taken out
- Merlin - after being tethered to Excalibur, Merlin's Darkness grew within him
- Killian Jones - when Emma tethers a dying Killian to Excalibur instead, until the darkness is taken out
- Rumplestiltskin - the current Dark One, darkness temporarily taken out of him but eventually returned
- Rumplestiltskin - the Wish Realm version of the original Rumplestiltskin is also the Dark One
OriginsCenturies ago, after Nimue used her newfound magic from the Holy Grail for evil, the Darkness takes root inside of her and she becomes the first Dark One, being powerful enough to trap Merlin. Nimue lives in all dark ones after she dies.
The idea of the Dark One's curse is that only one person can be cursed at a time. Nimue the original Dark One, created the the Vault of the Dark One. After she created it she emerged the vault. The Dark One was then killed with the Dark One's dagger. The position and power of Dark One then shifts to the person who stabbed the Dark One with that dagger, and so on. Zoso eventually kills the Gorgon the Invincible and becomes the Dark One himself. Down the track, he tricks Rumplestiltskin into killing him with the dagger, and therefore Rumplestiltskin becomes the Dark One.
When someone is the Dark One, they possess incredibly unlimited power. They are immortal, unless fatally wounded with the dagger or they are fatally injured in an area without magic, in which the Dark One's name would simply vanish from the dagger and the Dark One's curse would end forever, which is what nearly happened in the case of Rumplestiltskin. If the Dark One stabs himself with the dagger, then it is the same case and there is no new Dark One. However, the Dark One can be resurrected with the Vault of the Dark One.
The Dark One's appearance and behaviour change explicitly. Their skin turns grey and scaly, their eyes become an animal shade of brown and their voice changes. As time goes by, the Dark One also exhibits and gains some murderous traits, becoming less merciful and more corrupted with the dark magic that is now flowing through their body. For example, Rumplestiltskin turned someone into a snail and crushed them, because that person accidentally and barely injured Rumplestiltskin's son Baelfire.
- The Dark One's Curse is based on the beast's curse from Beauty and the Beast.