Board Thread:Spoilers!/@comment-26443838-20151009221621/@comment-1894786-20151016023048

NickyHelp wrote:

8Rob is right that the dark one can't kill him or herself with dagger when the darkness is still in a body. Nope, in Season 2 Cora very clearly said that if the current Dark One dies with no one to take the power with the Dagger, the Curse is over. Which implies that the Darkness would die with them.

In Season 3, it's made explicit that for Peter Pan to die, so must Rumple. Though it's never specified why that is, but that's the subject for another discussion. Then in Quiet Minds, they say that the Vault of the Dark One can bring back the most recent Dark One... from the dead.

Rumple died, and the Darkness died with him, because it didn't have another host to go to.