There’s a reasonably credible fan theory about Supreme Leader Snoke from Star Wars: The Force Awakens. And actor Andy Serkis, who provided the voice and the motion capture for the villain, isn't feeling the power of this speculation.
As we know from Star Wars: The Force Awakens, Lord Snoke is the mentor to Kylo Ren, a Jedi-in-training turned murderous. Although their relationship is never described as such, it’s similar to the Rule of Two structure of the Sith lords. (J.J. Abrams has gone on record to say that Kylo is not a Sith; he made no such comment about Snoke).
If you recall, there’s a scene in Star Wars: The Revenge of the Sith in which Chancellor Palpatine (later revealed to be Darth Sidious) discusses the most powerful Sith lord ever born, Darth Plagueis the Wise. He was so powerful, he was able to cheat death, until his apprentice - strongly suggested to be Sidious, himself - murdered him in his sleep.
Not according to fan theories, which claim that Plagueis cheated death yet again to return as Snoke. Evidence? The music from the scene in question in Revenge of the Sith, “Palpatine’s Teachings” is eerily similar to the music played when Snoke appeared in The Force Awakens, “Snoke” (Listen for yourself, here and here).
But Serkis isn't taking any of that Sith. According to Entertainment Weekly, Serkis said that character was a brand new addition to the galaxy far, far away.
“Supreme Leader Snoke is quite an enigmatic character, and strangely vulnerable at the same time as being quite powerful,” Serkis says. “Obviously he has a huge agenda. He has suffered a lot of damage. As I said, there is a strange vulnerability to him, which belies his true agenda, I suppose.”
So, there you have it: Serkis himself tells the world that our theories are wrong.
But it doesn’t stop me from thinking that Rey is a clone of Luke Skywalker’s missing hand—a hand that hadn’t been found when his lightsaber was recovered.