10 Star Wars Details Only Explained Outside Of The Films
9. The Nature Of Force Dyad - Rise Of Skywalker Novelization)
One of the main plot points brought up in The Rise Of Skywalker is giving a name for what Snoke did to Rey and Ben to connect them through the force, and how that connection is not only still there after The Last Jedi but has only gotten more intense. The phenomenon is called a force dyad, but not much is explained in the film beyond the name.
But a running theme you'll find in this list is that Rae Carson's novelization of the film is responsible for filling in most of the gaps left by the movie due to Abrams' pathological aversion to exposition (a blessing in 7, a curse in 9). Case in point, the first example of this being that she gives slightly more explanation towards how the force dyad works.
For one, the dyad is the only reason that Rey and Ben were even able to take on the Emperor and resist his influence at all. It's a connection between the two, not just in the force, but on a deeper, spiritual level.
Would've been nice for this to be explored in the movie for some much needed thematic undercurrent, eh Abrams?