As with any major blockbuster, numerous drafts of scripts are made and oftentimes do not even come to resembling what you saw on screen.
For example, 'Good Will Hunting' was originally an espionage thriller (really), while the likes of 'Blade Runner' had a vastly different spin in the original drafts. With that in mind, a draft of the ninth 'Star Wars' movie has leaked online and was pretty different from 'Star Wars: The Rise of Skywalker'.
The draft was reviewed and discussed by Robert Meyer Burnett's podcast, Robservations, and was independently verified by AVClub as genuine. As you'd expect, the draft tells an entirely different story from what people saw in cinemas. For one, the title was different - 'Star Wars: Duel of the Fates' - and the Emperor had only one scene in the movie, and as a hologram. What's more, Kelly-Marie Tran's character from 'The Last Jedi' had a much more significant role.
Colin Trevorrow's draft was submitted in December 2016, just a week before Carrie Fisher's death, which meant that Princess-General Leia had a much more significant role in the story. Not only that, Luke Skywalker also appeared in the script in a more significant way - as a Force ghost who haunts Kylo Ren. Other changes included Rey creating her own lightstaff, Kylo Ren's face being severely damaged and remade by Mandalorian armour, not to mention quite a significant portion of the story being set on Coruscant, which featured in the prequel trilogy.
A number of the characters featured in 'The Rise of Skywalker' didn't exist in Trevorrow's draft, such as Zorii Bliss or the fan-favourite droid mechanic, Babu Frik. That said, there were a number of new ones, including a character known as Tor Valum, who was the Emperor's mentor and is described as a 7,000 year-old alien with tentacles and sounds like an octopus. The story in the script goes that Kylo Ren finds a hologram of the Emperor that detailed what was to happen in the event of his death when Darth Vader had turned Luke Skywalker to the dark side. Essentially, Vader was instructed to bring Luke Skywalker to Tor Valum for training, in the same way Luke Skywalker went to Yoda in 'The Empire Strikes Back'.
All in all, it's definitely different and feels more in line with what Rian Johnson was trying to do in 'The Last Jedi' than what 'The Rise of Skywalker' ended up being. As with just about everything in 'Star Wars', it's going to please some people and piss off other people.
If you've got about two hours to spare, you can watch the entire podcast here with Burnett's discussion and review of the draft.