Jedi Knights Luke And Rey

Despite that I've heard that Star Wars Episode 8 will be a lot darker than Episode 7, I'm sure Luke and Rey will be well prepared for battle. I have even heard that the Knights of Ren will be shown in Episode 8. So it wouldn't surprise me that Luke and Rey will face them. Kylo Ren isn't the only one they'll have to deal with. I'm sure that they will deal with another unknown darkside user. I'm not sure about the Supreme Leader Snoke. I guess Luke and Rey will face him. But I think it won't happen in Episode 8. It will only happen in Episode 9.