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 the Battle of Endor — that's one year after Grand Admiral Thrawn's return, retaking of much of the Empire, and death — Luke hears rumors of a new Emperor taking the reigns. Enter Palpatine, having drifted his way to a clone body 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' EU canon is more internally consistent than most, but this series tends to be ignored fairly often, mostly due to all the retrogressive 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. Mara, having gone to the Dark Side herself for a while, also suggests that Luke 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. Additionally, the E-wing starfighter makes its debut, and in later books and comics would become one of the most common go-to machines when a writer wanted to utilize a fighter other than the four Rebel fighters from the films.However, with the release of the prequel trilogy, Palpatine's resurrection through cloning is made much more in-character to the point that it almost seems like a Call Forward. He apparently never discovered the secret of eternal life, but settled for clones instead.Last but not least, this comic also brought back Boba Fett ("The Sarlacc found me somewhat indigestible"), who made many further EU appearances post-Return of the Jedi as a result.
All There in the Manual: You know that hump-backed ship in Dark Empire that was briefly seen when Luke is first brought to Byss? Well, that ship was the Bellator-class dreadnought, which was created at some point during the Empire's creation as a fast dreadnought and successor to the Mandator I and Mandator II-class dreadnoughts. Also, the ISD-like large ships frequently seen in the series are the Allegiance-class battlecruisers, which were an example of the Star Cruiser line of Imperial Naval vessels, of which the Allegiance (the ship that the New Republic blew up before they could send a full transmission) was also a part of (and possibly the lead ship). The small Star Destroyers that are sometimes seen in the comics, and most certainly seen during the instance where the Allegiance was blown up were Procursator-class Star Destroyers. Lastly, the odd Star Destroyer-like vessel that had what resembled towers seen in Luke's arrival on Byss was the Secutor-class Star Destroyer, a carrier-type Destroyer that was created either during the late Clone Wars or the early formation of the Galactic Empire. This info was first revealed in the guidebook The Essential Guide to Warfare made in 2012, and their names were given in the Endnotes, and their names and detailed designs were also supplied by fan artist Ansel Hsiao.
Also, the name of the empire that Palpatine was running, according to the Essential Atlas, was the Dark Empire, just like the comic book series.
The rare but brilliant Dark Empire Sourcebook for the old RPG makes a world of difference in understanding the comic and appreciating its scope. It also tries to fix some of the Continuity Snarl referred to below that the nigh-simultaneous release of Timothy Zahn's books caused.
Always Night: Byss is ground zero for Dark Side energy, giving it a sickly blue glow.
And I Must Scream: Palpatine's final fate is described as "disembodiment in darkness, perpetual madness as if to always live with an open wound; terror without respite".
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.
Big Bad: Palpatine, as in the original film trilogy (and later, the prequels).
Blond Guys Are Evil: Palpatine's younger clone bears a strong resemblence to Blade Runner's Roy Batty, and he's about as stable to boot.
Evil Redhead: At least one of Palpatine's clones sported red hair.
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."
Clone Degeneration: Palpatine's clones have progressively shorter lifespans due to them being less and less natural, and thus not as resistant to the corrosive effects of his Dark Side powers.
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.
Cool Ship: Eclipse I and II. Take a Super Star Destroyer and stick a scaled-down version of the Death Star's superlaser in it.
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.
Fake Defector: Luke "turned" to the Dark Side with the intention of destroying it from within. Unfortunately for him, it backfired.
False Utopia: Byss, the Emperor's throneworld. It's beautiful and serene, with the billions of inhabitants (including a number of Alderaanian expatriates) living out their lives in harmless bliss. Little do they know that they are the fuel that powers Palpatine's sorceries ...
Gambit Roulette: Also the whole clone plot. 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 its to be expected.
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.
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.
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.
Rasputinian Death: The entire Skywalker-Solo clan kills Palpatine at various points, including Han and Leia's unborn son!
Sanity Slippage: Palpatine was first shown to have some degree of self restraint after his first death. Upon his third return, however, he immediately uses the Galaxy Gun to wipe out various worlds rather than fortify his gains. The Essential Atlas released years later even lampshades it by having Crix Q5 stating that his madness deepened due to having to return from the dead a third time.
Shout-Out: The Galaxy Gun's stance as a superweapon capable of firing missiles for an exceedingly long distance is basically the sci-fi version of the (never finished) Vergeltungswaffe 3 cannon, a cannon that was under development in Nazi Germany-controlled Poland that was capable of firing intercontinental missiles. It was planned to bombard London from two bunkers in the Pas-de-Calais region in then-Nazi Germany-controlled France during World War II.
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 mentioned below. It's explained more in other sources.
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, Empatajayos 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.
Title Drop: The name of Palpatine's faction is the exact same as the title of the overall series as well as the first two parts of the three part series. Unlike most examples, though, the Empire in question was never given a specific name until several years later, when the events of the series were covered in the Essential Atlas. Something similar would exist with the sequel series, Crimson Empire (not to be confused with the unrelated video game of the same name).
Trap Is the Only Option: Luke willingly steps into the same trap which snared his father. He believes it's the only way he can destroy the Empire from within, or something; the logic basically relies on Rule of Cool.
Villainous BSOD: Palpatine loses control of one of his Force storms, which tears his body apart.