2. Qui-Gon Jinn
The Rise Of Skywalker isn’t the only Star Wars movie to open up new concepts and then never finish them (for example, Lando Calrissian’s daughter). It also happened in Revenge of the Sith, when Yoda and Obi-Wan are discussing their places of exile.
Yoda tells Obi-Wan that his old master has discovered the path to immortality and can thus be communed with on Tatooine, where Obi-Wan will be continuing his training.
This is, of course, in reference to Qui Gonn Jinn, the man who’s pretty much at fault for the destruction of the Jedi order, since he decided to train Anakin (maybe I’m being dramatic).
Whatever the case, Qui Gonn was an excellent character and a stellar Jedi and I, for one, loved Liam Neeson’s portrayal of him. I wonder if there are any plans to reprise the role with Neeson, but whatever the plan, it’s hard to avoid the inevitability of Qui Gonn being heavily involved, since Yoda made it clear that this would be a big part of Obi-Wan’s training.
So we have that to look forward to. Even more so, though, is No. 1.