I feel like Rumple and Killian were both so much better as the Dark Ones but they were villain a la originale anyway....Emma is going against every fiber of her being as a Dark One plus she's trying to convince her family that it was something they did that pushed her off the edge so as to prevent Killian from finding out the truth so it's almost like she's trying too hard to convince everyone that she Evil Supreme
Zoso tricked Rumplestiltskin because he couldn't deal with the burden any longer, and Rumple feared his heart growing completely black, and having been the Dark One for 200 years, he was very close to fulfilling that little prophecy of snuffing out the light for good. Makes me wonder how far along Zoso was, and what would've happened if the Apprentice didn't pull out the darkness from Rumple's heart. Also, how dark is Emma's heart now? The amount of darkness that Rumplestiltskin accumulated must have transferred to Emma, didn't it? Maybe it transferred in the form of that rumple that follows Emma around. I'm pretty sure Rumple himself didn't have a Dark Zoso following him, or he would've given in pretty damn quick.
I think Rumple was a lot more willing to embrace the Darkness so he didn't need a tempting influence; the only reason the Darkness appears to Emma is because she is reluctant to do so.
I honestly don't believe Rumple is dead I believe e Emma is talking to Rumple and he has a plan I feel like maybe he is just using Emma.... but who knows.....
+geyn Rumple's not dead he's in a coma. The person talking to Emma is not Rumple, but rather a manifestation of her dark powers that has chosen to look like Rumple.