I really liked that J.J. brought back Palpatine in The Rise of Skywalker, and I thought it was an absolutely necessary thing to do.

By bringing him back, it ties all nine Skywalker saga movies together as one cohesive, overarching story and makes The Rise of Skywalker feel like an actual series finale to the saga, it feels like there really is one overarching villain for the saga rather than just killing him off for good in Return of the Jedi and then having Kylo Ren be the villain in the last trilogy.

He is so important to the saga, and had he not been included as the final villain of the trilogy, and, by extension, the saga, then it would’ve felt like something was missing. We have more of an established connection with him over the first six films than with Kylo Ren or Snoke or Plagueis or the Yuuzhan Vong from Legends or Maul.

Even J.J. Abrams, director of both The Force Awakens and The Rise of Skywalker, agreed that, “…when you look at this as nine chapters of a story, perhaps the weirder thing would be if Palpatine didn’t return. You just look at what he talks about, who he is, how important he is, what the story is — strangely, his absence entirely from the third trilogy would be conspicuous.”

His return is also a metaphor for the current generation being affected by and facing the same struggles and battles as the previous one, something really impressive as a huge part of Star Wars deals with themes of the past.

It is also worth noting that his return pays off his interest in immortality as hinted at in Revenge of the Sith, only for his spirit to be trapped in a deteriorating clone as he is very much horrible at making clones — a fate worse than death.

It also works because we were shown who he was and what he could do throughout the saga — he is the Dark Lord of the Sith who is a mastermind, an orchestrator, a liar and master manipulator willing to do whatever it takes to take over the galaxy. He’s literally played both sides during the prequels, and lured the Rebels into a trap in Return of the Jedi.

Also, what adds to the finality of his return is that, in Star Wars, he is the embodiment of pure evil, he is essentially Satan, but in space. He cares about no one but himself, he made Anakin lose everything he loved and put him into a suit of hell for twenty-three years. Even in just Return of the Jedi, he spews out his physical hatred towards Luke via Force lightning and this is very obvious via acting and facial expressions.

Many point out that it invalidates Anakin’s redemption in Return of the Jedi, but it doesn’t, really. He only killed Palpatine to save Luke, his last remaining loved one, not necessarily to save the galaxy, topple the Empire or fulfill the prophecy as the Chosen One — his destiny as the Chosen One was merely there in the prequels to put in some additional weight to his fall.

Anakin could’ve thrown Palpatine into a ball pit and his sacrifice would still retain the same meaning — he did it to save his son. Luke dying ten minutes afterwards from some kind of disease or cancer would’ve made Anakin’s sacrifice all for nothing. His motivations were so obvious, just by watching the scene alone in Return of the Jedi.

I’ve seen some counter this by pointing out that Luke died anyways in The Last Jedi, but guess what? His sacrifice inspired the galaxy in a time of hopelessness, even children enslaved by some of the worst, and it’s also why the Resistance has more members in The Rise of Skywalker than at the end of The Last Jedi, and certainly why the galaxy’s citizens followed Lando to Exegol.

Furthermore, as stated, it gave Palpatine a fate worse than death — because he is so horrible at making clones, let alone any lifeform, his spirit is trapped in a deteriorating clone. Of course, he rejuvenates himself anyways, but he clearly hadn’t returned to the wider, known galaxy and Rey defeated him shortly afterwards.

Not to mention that Anakin did bring balance to the Force. He confirms himself that he did bring balance to the Force — he tells Rey to “bring back the balance, as [he] did.” Furthermore, Luke mentions in The Last Jedi that, “For many years there was balance, until I saw Ben.”

Critics also act like there was no explanation for how he is still alive after blowing up in a reactor shaft shortly before the second Death Star blew up, except he straight-up confirms he’s died before, and his main motivation is literally to possess Rey if she were to kill him in anger so he wouldn’t be trapped in that shitshow of a clone. Put two and two together, and one can infer that he transferred his spirit to this clone after Darth Vader killed him in anger.

The final argument I’ll be addressing is his apparent “lack of set-up or foreshadowing”.

The whole point of The Last Jedi is that everything is hopeless with the First Order in charge, until Luke Skywalker — the legend, the man who saw good in Darth Vader and turned him back to the light — shows up to save the day and inspires the galaxy, igniting a spark of hope that the First Order is going to be defeated, one day.

The scene with Temiri Blagg at the end of The Last Jedi drives this point home; he, like the other children at Canto Bight, are slaves, but, despite that, he still has a sense of hope — their enslavers represent the First Order and how they are in charge of the galaxy, and the children represent the galaxy itself… and us, the audience —, the final shot of the film is literally him looking off to the stars with hope.

If J.J. Abrams or Rian Johnson foreshadowed Palpatine’s return in The Force Awakens or The Last Jedi, it would take that away, because, now, we would be asking ourselves, “Why should we be hopeful that the First Order will be defeated when Palpatine is just going to come back and fuck everything up?”

Even then, in the way “I am your father…” in The Empire Strikes Back was “foreshadowed” by Obi-Wan being emotional before telling Luke what happened to his father in A New Hope, the same applies to Palpatine’s return:

During the opera scene in Revenge of the Sith, Anakin asks him if it is possible to “learn this power,” obviously referring to Plagueis’ desire to keep himself alive, and Palpatine responds, “Not from a Jedi,” as he grins at us and dramatic music begins to play as the scene cuts away — he implies he does know how to cheat his own death.
Most infamously, “Emperor’s Theme” is played very prominently when Snoke mind-probes Rey in The Last Jedi. Similarly, vocals from the opera music from Revenge of the Sith play during the “awakening” scene with Snoke and Kylo Ren in The Force Awakens, something people initially interpreted as potential foreshadowing for Snoke being Plagueis.
Kylo Ren asks Vader’s helmet to show him the “power of the darkness” again, implying this has happened before, at least by some sort of supernatural force. It could initially be interpreted as Snoke, but it does get some payoff in The Rise of Skywalker: “I have been every voice you have ever heard inside your head.”
Snoke acts very similar to Palpatine and even repeats his dialogue in The Last Jedi: “Welcome, young Skywalker. I have been expecting you.” “Young Rey. Welcome.” “It was I who allowed the Alliance to know the location of the shield generator.” “It was I who bridged your minds.” Obviously, Palpatine would want Snoke to be a copy of himself.
Even Snoke’s guards share the exact color scheme with Palpatine’s guards. Palpatine would very much want both sets of guards to look similar to each other in terms of color scheme, and he still uses red-colored guards in The Rise of Skywalker.

Over, and out.