8. Snoke Will Confirm He's Darth Plagueis
In The Force Awakens, Andy Serkis Supreme Leader Snoke was a mysterious figure seen only a handful of times via a huge hologram projected somewhere within Starkiller Base. In Episode VIII though, it seems likely that well see him in the flesh (given that he summoned General Hux and Kylo Ren to his location at the end of VII).
This presents the possibility of longer scenes involving Snoke. Hell surely get more dialogue, which could possibly allow room for an explanation of the massive scar on his head and other assorted deformities around his face. The online community has one big theory about this that Snoke is Darth Plagueis, the Sith Lord that trained Darth Sidious (AKA Emperor Palpatine).
Palpatine told the story of Plagueis to Anakin in Revenge Of The Sith, explaining that this powerful Sith could influence the midichlorians and create life as well as keeping those he loved from dying before he met an untimely demise at the hands of his apprentice, the then-young Palpatine. But if Plagueis could truly cheat death, perhaps he survived without Palpatine knowing.
In Episode VIII, as Snoke continues training Kylo, perhaps talk will turn to his former apprentices... the scars from his lengthy past... building up to the sizeable reveal of Snokes alternative moniker, Darth Plagueis. Itd be one hell of a talking point, and a neat way to slightly legitimise the prequels.
There's been reports recently that Serkis has denied this, however, that doesn't seem to be the case.