As The Dark One who is a very powerful wizard who can only be defeated by his dagger the dagger is wavy and silver with the name Rumpelstiltskin wrote on it but who ever stabs him with the dagger becomes the new Dark one and their name appears on the dagger. But the dagger can also control him making him do whatever you want so he's hiding it somewhere he only knows. He also stole a curse called the Dark curse so he can cast it to take him to a world without magic to find his son Baelfire. 