It's presumed that probably this'll involve Vader's wayfinder to Exegol, which Kylo finding on Mustafar starts the movie. I'm kind of curious if there's any relationship between Vader and the Sith Eternal.

The latest storyline, of course, is tied somewhat to Episode I, with Vader teaming up with Padme's Episode I decoy Sabe (Played by Keira Knightley in the movie)