A series of Star Wars Expanded Universe comic books (Dark Empire, Dark Empire II and Empire's End -- collectively called Dark Empire) released between 1991 and 1997. It was also made into an audio drama, which had a somewhat modified script. A sample can be heard here.
Six years after his death -- one year after Grand Admiral Thrawn's return, retaking of much of the Empire, and death -- Palpatine comes back, having drifted his way to a clone in a hidden place at the center of the galaxy. And boy, does he have a revenge plan. It involves turning Luke Skywalker to the Dark Side, Body Surfing from clone to clone in order to be immortal, using a planet-destroying gun, sending out machines called World Devastators to chew up the Mon Calamari homeworld, and enslaving the universe. He's been plotting to enslave the universe since he was smacking other babies with his rattle, so of course he's not finding new goals now.
Star Wars Expanded Universe canon is more internally consistent than most Expanded Universes, but this series tends to be ignored fairly often, considering all the important things that happened during it. A few things are acknowledged. Han and Leia had a son that they named Anakin, who went on to be pretty important. The first Rogue Squadron game, mostly set between the movies, had a final level where the player was Wedge Antilles on Mon Calamari, trying to take down the World Devastators. In the Hand of Thrawn duology, the subject of the Emperor's return comes up and Mara Jade - who was his Hand and could hear his instructions from across the galaxy - doubts that this Emperor was really Palpatine, and Mara speculates that Luke, having gone to the Dark Side for a while, has been slightly tainted by it ever since. Luke Skywalker and the Shadows of Mindor has a Body Surfing villain think about how Palpatine had a similar plan to his, but involving clones, and since the villain in question was never able-bodied, he's going a different route. Last but not least, this comic also brought back Boba Fett, who made many further EU appearence post-Return of the Jedi as a result.
- A God Am I - Palpatine's final plan is either this or an Assimilation Plot, your pick
- Attack Its Weak Point - Averted; the Galaxy Gun has no real weaknesses whatsoever, and the heroes have to resort to ramming it with Palpatine's hijacked Star Destroyer in order to disable it.
- Ax Crazy: Palpy is nuttier than ever. It is also implied that his loss of sanity was the direct result of having to frequently possess clones of himself, especially genetically-tampered ones.
- Back From the Dead: Palpatine, natch, but also Boba Fett; this was the first 'canon' EU source to Retcon Fett's death-by-Sarlacc in Return of the Jedi.
- Badass Boast:
Palpatine: I've played along with your Jedi dueling games long enough! Now you will experience my full potency... I live as energy... I am The Dark Side!
- Badass Normal - Han kills Palpatine. Actually, several characters do this over the series, but Han kills him the last time and he doesn't come back.
- It should be noted, however, that it was implied that Palpatine deliberately held back enough power to allow himself to be shot by Han in order to possess Anakin Solo.
- Barbie Doll Anatomy - Palpatine sure gets a lot of tropes in this one.
- Becoming the Mask - Luke
- Big Bad - Palpatine, again.
- Body Backup Drive: It's mentioned that The Emperor kept a number of cloned bodies for the purpose of this trope.
- Continuity Nod - "If there's a dark center to the universe, this is it."
- Cloning Blues: During his time as the Emperor's apprentice, Luke lets himself get cloned twice. Instead of another Luuke, he's given a pair of immensely strong mutated bodyguards, who are left behind to die when Leia rescues him. At least Luuke got a name.
- Cloning Gambit: Sort of. It's the same Emperor Body Surfing from one clone body to the next, and the same Emperor who died on the second Death Star.
- Decompressed Comic - This comic goes to the other extreme. Important events happen in a few panels or entirely off-page.
- Demonic Possession: Palpatine's final chance at survival involves doing this to Anakin Solo.
- The Dog Bites Back: You know those two Dark Jedi that acted as Palpatine's aids, Nefta and Sa-Di? Well, after Palpatine was gone, they decided to follow Luke's example and slaughter all the clones of Palpatine in order to ensure he doesn't come back, an action that got them killed by Sedriss. Bear in mind that until his demise on the Eclipse, they didn't even attempt to betray him, making it more this trope rather than The Starscream.
- Evil Cannot Comprehend Good: Sidious still underestimates the Papa Wolf.
- Fake Defector: Luke "turned" to the Dark Side with the intention of destroying it from within. Unfortunately for him, it backfired.
- Fan Disservice - Luke fighting Naked!Palpatine.
- One panel has a clear shot of Palpatine's crotch. Either his, er, Dark scepter and orbs are edited out, or Palpatine didn't think they're necessary.
- Fan Nickname - "Wankatine" for the overpowered Palpatine featured in this series.
- "Bowie-peror" for young clone Palpatine's resemblence to David Bowie.
- Freud Was Right - the Galaxy Gun
- From a Single Cell - See Cloning Gambit
- Genetic Engineering Is the New Nuke - or Sith alchemy is the new nuke. Also cloning.
- Heel Face Revolving Door - Luke first joins Palpatine and later Leia redeems him.
- Heroic Sacrifice: In spades.
- Hey, It's That Voice!: The audio dramas have John Cygan, who voices Canderous in Knights of the Old Republic and Solidus Snake, voicing Luke, Wedge, and random minor villains.
- Idiot Ball - Collectively, for all the Alderaanians who went to Byss because the guy who DESTROYED THEIR PLANET wanted to make amends.
- Immortality Immorality - Palpatine plans to enslave the entire universe and draw on their life energies to perpetuate himself, with Darth Farmboy by his side of course.
- Intentional Engrish for Funny - Bizarre lines like "Aren't I the master of all the Jedi?" and "Unngh, the Corellian has killed me." become even worse when you consider the book is written in English!
- In the Blood - Luke's the picture on the In the Blood page. He took an enormous ship and crash-landed it safely during a battle, then resisted Palpatine's urgings, then turned with the best of intentions, then went evil for a while, then was redeemed by a relative's love. While under Palpatine he was given his father's title, Supreme Commander of the Imperial Forces, dressed in clothes much like his father's Custom Uniform, and given a mechno-hand very like Vader's.
- Irony - Darth Sidious, Chessmaster extraordinaire and the Sith'ari, dies for the last time when Han Solo, a non-force-sensitive, shoots him.
- Lost Tribe - the Ysanna
- Meaningful Name - Anakin Solo. Also, (a)Byss.
- Mind Rape: After Leia jars Luke into acting openly against the Emperor, Luke tries to kill all of the Emperor's clones but is caught and beat down. But the Emperor doesn't kill him. In the radio version there's an entire sequence.
Emperor: You. Are. Nothing.
Luke: Where am I?
Luke: No - Help me-
Emperor: There is no one. There is only the Dark Side.
Luke: I... am... a Jedi. Aaaaah!
Emperor: You are not Jedi. You are nothing. You have no name.
Luke: My name - is - Skywalker! AAAAAAH!
Emperor: YOU. HAVE. NO. NAME!
Emperor: Listen to the Dark Side. You have no name.
Luke: I have... *dully* no name.
Emperor: You serve the Dark Side.
Luke: I... s-serve...
- Mobile Factory: World Devastators.
- The Mole - Luke. Oddly, The Empire sees nothing odd about taking orders from Lord Skywalker.
- Naturally, this makes him a Darth Mole.
- My Death Is Only the Beginning: Implied to be the source of Palpatine's increase in overall force powers.
- Narm: Declarative statements against dramatic backdrops, bold, italics and exclamation marks all over the place.
- Papa Wolf - Han
- Powered by a Forsaken Child - Again, Palpatine's immortality. Is there any trope (besides Always Lawful Good) that this guy doesn't fall under?
- Pregnant Badass - Leia. Possibly even more than she was during her first pregnancy.
- Power Creep, Power Seep - The battlefleet-destroying Force Storms that Palpatine never had before. Palpatine is so absurdly powerful in this series that many fans call him "Wankatine".
- It's hinted that this power was actually the result of his returning from the dead, so its more of a case of "My Death Is Only the Beginning". The fact that he was also extremely powerful even before his death and revival, which was implied in Darth Plagueis to be due to his being literally conceived by the Dark Side of the Force might also have been a contributing factor as well.
- The Power of Friendship - what finally keeps Palpatine from coming back again and again.
- Sean Connery Is About to Shoot You - The cover of the final Dark Empire II series issue features Leia firing a pistol aimed directly at the reader.
- The Starscream: The head physician who orchestrated the cloning process is pretty much this, as he was implied to have engineered the shortened life-span of the clones since at least the Emperor's first death. Carnor Jax is definitely one, since he's the one who got the physician to do this in the first place.
- Staying Alive: The only explanation provided for Boba Fett's return is...
Boba Fett: The sarlacc found me somewhat indigestible.
- Taking the Bullet: Variation: After Palpatine was shot by Han Solo, his spirit did a last ditch effort to possess Anakin Solo. However, Emphajaros Brand intercepted the spirit and had it possess him so Anakin was spared, and then died from the injuries Palpatine earlier unleashed on him, taking Palpatine with him.
- Taking You with Me: Brand to Palpatine. See Taking the Bullet.
- They Killed Kenny - the entire Skywalker-Solo clan kills Palpatine at various points, including Han and Leia's unborn son!
- Villainous RROD - Palpatine loses control of one of his Force storms, which tears his body apart.
- Weapon of Mass Destruction - World Devastators, Eclipse- and Sovereign-class SSDs, and the creatively-named Galaxy Gun.
- What Could Have Been: It was originally intended that, instead of reviving Palpatine as a clone, the storyline would have involved the Empire hiring someone to wear a replica of Vader's suit to keep fear in the galaxy, but Lucas vetoed that option.
- What Do You Mean Its Not Symbolic - Palpatine at the center of the galaxy, not unlike Satan at the center of the universe
- Women in Refrigerators: Jem, Luke's Girl of the Week, who gets randomly killed by Palpatine's henchmen.
- Xanatos Gambit - Han kills Palpatine, making it so Palpatine can possess Anakin. Also the whole clone plot. In fact, it's generally Gambit Roulette. On the flip side, Luke loses to Palpatine, pretends to fall to the dark side, and thus gets close to him where he can sabotage the clones, but of course he becomes the mask. But it's Palpatine and Luke, so XanatosGambits are expected.