The first glimpse we get of Kylo Ren in Star Wars: The Rise of Skywalker, he's slaying down cultists on Mustafar and seeking out the Sith Wayfinder. He seems to have little trouble finding it and goes along his way to Exegol to meet his new Sith master.
Palpatine's introduction in The Rise of Skywalker seems a bit anticlimactic, but that wasn't always the plan. Concept art for a scrapped scene shows the original plot for Kylo's quest, and it reveals some interesting insights into his motivations heading into the final chapter of the Skywalker Saga.
The novelization of The Rise of Skywalker includes many new nuggets of canon and fleshed-out scenes. It's rare, however, for such an adaptation to include a whole sequence omitted from the film. In the second chapter, Kylo encounters The Eye of Webbish Bog, otherwise known as The Oracle: a blind giant with a spider-like creature atop its head that emerges out of an oily black lake. (Yes, it's just as awesome as it sounds and we're so sad it's not in the movie.
In the novelization, The Oracle warns Kylo of the oncoming danger, telling him that seeking the Wayfinder will make him encounter his true self.
The novelization goes into more detail describing the monster:
A giant emerged, a hairless creature sheening with wetness, bits of lake detritus clinging to its pasty skin. Its eyes were squeezed shut, but it could still see after a fashion, because draped over its massive bald head and across one shoulder was a second creature with long spidery tentacles. The two were locked in symbiosis. Kylo sensed the giant’s pain, as though it were a slave to the spidery being that clung to it. Yet neither could it survive alone.
This is the beauty of the novelization: the subtext of the monster benefiting from symbiosis would normally be difficult to pinpoint in film, but the book is able to say it outright. Kylo senses the Eye's pain through the Force, sure, but this isn't sympathy, it's empathy: Kylo himself is locked in a symbiotic relationship, a Force dyad, not knowing how to quite exist without the other.
So if the image was so poignant, why wasn't it included in the actual film? Well, it almost was. In an interview with Collider, creature and special make-up effects supervisor Neal Scanlan revealed his team built an actual model for the Eye of Webbish Bog and filmed a sequence with it. Considering how often CGI is used in Star Wars, the fact this would have been an entirely practical sequence is impressive.
Unfortunately, it came down to time. Rise of Skywalker already had quite a lot of storytelling to do, and J.J. Abrams and the editors decided the key takeaways from this moment could be inferred. Don't give up hope of ever seeing this guardian of Vader's castle, however. Later in the interview, Scanlan mentioned how he hopes he can bring the Eye back, possibly in a TV series like The Mandalorian. Perhaps later seasons will bring the bounty hunter to Mustafar?
Regardless of whether or not we see the Eye of Webbish Bog again, it's mere existence shows a dedication to the roots of Star Wars: Jim Henson-style creature puppets, unusual character design, and use of mystical encounters to flesh out a character's journey.
After all, Kylo finding the wayfinder was only the first step, but having the foreboding warning of his "true self" would have given him, and us, a glimpse into the epic path that lay ahead.