Darth Maul is back, for Season 3, and he seems to be fostering a need to take Ezra as an apprentice, more than ever. Here the two combine Sith and Jedi Holocrons.
We don’t know what Maul is up to, but it certainly can’t be anything good. There’s also the introduction of a very powerful Force being, named the Bendu (voiced by Doctor Who actor Tom Baker).
And it looks like Kanan and Ezra wake some sleeping Sith spirits. I know many will argue that George Lucas said the Sith couldn’t produce Force Ghosts, but to that I say: This isn’t Lucas’ Star Wars, anymore. And, there are instances of Sith Force Ghosts from the old EU books.
Next: Finally, Thrawn