He didn’t have much screen time in The Force Awakens, but he is in fact the total baddie in the reviving franchise.
As to why he is the villain, Serkis and Johnson vaguely explains his painful past. They say that he has unexplained rage against the Galactic Republic, and now on the Resistance. Serkis describes that there is a painful past behind the cruel dominating personality of the 9 feet tall humanoid.
“The thing about Snoke is that he is extremely strong with the Force, the dark side of the Force. He’s terribly powerful, of course. But he is also a very vulnerable and wounded character,” Serkis says. “He has suffered and he has suffered injury. The way that his malevolence comes out is in reaction to that. His hatred of the Resistance is fueled by what’s happened to him personally.”
Supreme Leader Snoke targets weak and wounded individuals such as Kylo Ren and General Hux to do his every whim. He exploits them, giving them false promises of power, and is willing to discard them if they are no longer useful.
“His training of Kylo Ren is not yielding what he wants,” Serkis says. “Therefore his anger towards Kylo Ren is intensified because he can’t bear weakness in others. Part of the manipulation is goading him with Hux and playing them off against each other.”
The Last Jedi will reveal that the First Order is far stronger than anyone else in the galaxy realized. “Despite the fact that the Starkiller Base has been destroyed and the Resistance has been putting up a fight, we will discover that the First Order has limitless resources in this one,” Serkis says.
Every painful experience has its scars. Rian Johnson also implied that we will learn a bit as to why Snoke is deformed. He says that everything about him will slowly unwrap in this year’s and future other installments.
“You witness his physicality,” Serkis says. “His body is kind of twisted up like a corkscrew, and so he has limited movement. His aggression and his anger is contained and restricted by that physicality.”
As for living in luxury, he loves showing it off.
“Oh, absolutely. He’s slightly oligarch,” Serkis says. “You know, he’s not afraid of showing his fineries. There is a luxury that’s native to him.”
You can see it in his throne room, and his scarlet-armored Praetorian Guard. “The way that his court is presented, he’s very totalitarian in that way and flamboyant,” Serkis says. “He enjoys that theatricality, I think.”