Star Wars Episode IX: 8 Consequences We'd Like To See With The One-Year Time Jump
5. Luke As A Force Ghost
It's common knowledge at this point that Mark Hamill will be returning, in one way or another, to round out the franchise as Luke Skywalker.
Considering that Luke met his fateful end in the closing moments of Last Jedi, the easy assumption to make is that Luke will be a Force Ghost when we see him again.
As has been detailed in various Star Wars media countless times before, the transition from a living person to an entity of the Force is not exactly an easy one. For instance, it took Qui-Gon Jinn over a decade to even figure out how to pioneer this transition in the first place. Later Force Ghosts like Obi-Wan and Yoda had an easier time with it, but clearly grew more powerful and accustomed to it with time.
Thus, the year in-between films will have given Luke ample time to hone this power and play an integral role in the film. Considering that Last Jedi finally delivered on Obi-Wan's threat to Vader all those years ago on the Death Star about becoming "more powerful than you can possibly imagine" in the form of showing off Force Ghost Yoda's immense powers, Luke could be even more powered than before.