I kind of wonder if Palpatine created Anakin to act as some sort of vessel in case he died, and that is also part of why he turned him into Vader, because he needs a dark side vessel. That potential is passed on through the Skywalker line, so Snoke corrupts Ben Solo into Kylo Ren to be a new vessel for Palpatine. But the Force, being a things of its own, has a play as well: the spirit of Anakin Skywalker is given a vessel/champion too in the form of Rey. That explains how she is both a nobody and yet intimately connected to the lightsaber: she is a vessel though not a true reincarnation. The final battle will have two aspects, just like the prequel trilogy, but it will be partly metaphysical: Rey vs Ren, and Skywalker vs Palpatine. In this way Rey becomes "the Skywalker" and Ren "the Emperor/Sith" in new version of the dichotomy between the Daughter and the Son. Or something like that.