But as we see, or rather hear, in the trailer for Star Wars: The Rise of Skywalker, Emperor Sheev Palpatine, dark lord of the Sith, may not be as dead as we thought. He may have found his loophole between the worlds of the living and the dead, and merely bided his time until he knew the conditions would be optimal for another bite at the galactic apple. There were plenty of Jedi temples out there, and any one of them could have a portal similar to the one on Lothal. It wouldn’t be that much of a surprise, and honestly, it’s better than the clones that the previous Expanded Universe canon used to keep the character in the picture.
Article source: https://www.cinemablend.com/news/2470323/star-wars-everything-you-need-to-know-about-emperor-palpatine