How can you say jj is avoiding the prequels and the Eu? Maz clearly says the word "sith" during the cantina scene in force awakens, oh yeah and that all of the old flags hanging outside while they are walking in are pod racing flags from the tatooine pad races. Anakins included. And that phasma's suit is partially made from emperor palpatines old naboo cruiser/yacht. So let's make it clear and understood now that the new trilogy is making at least sub conscious links with the prequels because it must for the entire saga to be one clear story. I think (and I am speaking with what is considered canon) that it is perfectly logical to assume that the only person that could of stayed hidden under the emperor and darth Vader was the dark lord that was even master to the emperor and that the emperor assumed to be dead(we know that from episode 3) it's also perfectly logical to assume that for plot reasons, snoke wouldn't go under the title "darth" and that the topic of midi clorians would be a thing of the past, not just because jj is trying to avoid it. Even leaving the prequels out, who would be a bigger badder villain beyond even the emperor? And would be a complete plot twist and epic tie up for the whole 9 episode saga? And would also make sense in relation to what is canon? The guy who was even the master of the emperor meaning the mega master of the whole story. And there is only one time in the story that we hear who the master of the emperor was. Oh yeah and that he just coincidentally has potential power of stopping death. But is presumed to be dead? Probably not, what a twist!