The return of the Emperor, also known as Darth Sidious and previously known as Senator and then Supreme Chancellor Sheev Palpatine (yes, his given name really is Sheev) was teased in the first trailer for 2019's Rise of Skywalker . So fans have known for a few months that this was coming. While that may seem like a big reveal to give away in a trailer, it's not really that surprising in the grand scheme of Star Wars. Obi-Wan Kenobi's (Alec Guinness) death in A New Hope didn't prevent him from appearing as a Jedi Force Ghost in both The Empire Strikes Back and Return of the Jedi. Yoda (Frank Oz) also popped back up to have a full conversation with Luke (Mark Hamill) as a Force Ghost in The Last Jedi after he died. It's all very horcrux-y, to mingle Harry Potter lore with Star Wars, but since Palpatine's return is not fully explained, we're left to assume that somehow, Palpatine figured out a Dark Side equivalent to the Force Ghosts.