At the end of Return of the Jedi, Emperor Palpatine is killed by being thrown into the
Death Star’s reactor.
However, in Legends, the old Star Wars timeline, Palpatine actually survived this encounter
and was able to come back to life in a new physical body.
So how was he able to do this?
At some point prior to his death, Palpatine learned the dark side ability called transfer
essence.
This ability allowed its user to preserve and transfer his or her consciousness into
another body or even into an inanimate object.
Powerful Sith Lords of the past used this power to cheat death, usually by transferring
their force spirit into a sith artifact or tomb, forever hunting those who came into
contact with them.
Other Sith Lords straight up took control of other people’s bodies, and they were
able to continue actively living like this for as long as they wanted, by doing the same
thing over and over again, whenever their current physical bodies died out.
There was a risk though with possessing other people’s bodies, which is if the person
being possessed was somehow able to resist and repel the possession, then the sith spirit
would be sent into the Void, which is basically the Hell of Star Wars.
There, the sith spirits would wander around forever and go mad from endless torment.
A way around this was to create clone bodies that didn’t possess a conscious, which is
exactly what Palpatine did before his first death.
When he died, Palpatine transferred his force spirit into a clone body that he had stored
on the planet Byss.
After a successful transfer, he waited to recover and gain his strength back, before
revealing himself to the New Republic.
6 years later, almost right after Thrawn was defeated, Palpatine would finally come out
of the shadows and make his moves in retaking the galaxy once more.
He deployed newly construed super weapons that took the New Republic by surprise and
devastated their forces.
He also kidnapped Luke Skywalker by teleporting him using a wormhole to his citadel on Byss.
When he confronted Luke, he tried once again to convince the Jedi to join him and rule
at his side.
Although Luke dismissed Palpatine’s persuasions, he ultimately kneeled down and accepted to
be his apprentice, knowing that he wouldn’t be able to defeat Palpatine in a fight at
his current state, and that he needed to learn the secrets of the dark side if he were to
ever defeat the sith lord.
Palpatine knew that Luke was deceiving him from the beginning, but he let the Jedi continue
on.
Palpatine understood that no matter how hard Luke would try, that he would eventually fall
to the darkside and become his servant, as was the story for any Jedi that tried to learn
the dark side without falling to it.
And he was right, as Luke eventually succumbed to the darkside and became a willing minion
of Palpatine.
However, Palpatine’s gamble on obtaining one of the most powerful force users to his
side would eventually backfire, as Luke would later be turned back to the lightside with
the help of his sister, Leia.
Back to the lightside and with the new knowledge of some of the dark side’s secrets, Luke
fought Palpatine and was able to defeat him and lead him to his death.
Despite this, Palpatine was able to keep on coming back in his new clone bodies that he
had stored throughout the galaxy.
But that wouldn’t be the case for long.
As while Palpatine was in spirit form returning back to his clone bodies, two of his dark
side students betrayed him and proceeded to destroy all of his remaining clone bodies.
But their plot was foiled and they both were executed, with Palpatine being able to return
in the last surviving clone body.
This proved to be a major blow to the sith lord, as earlier another traitor within his
ranks sabotaged his clone templates, preventing him from producing any more viable clone bodies
for him to use.
And because of how consumed in the dark side he was, the dark side itself was literally
eating away his physical body, making him weak and old.
Desperate to be healed, Palpatine went to Korriban and asked for guidance from the ancient
spirits of past sith.
They told him to possess Leia’s newborn son, Anakin Solo, and take his body for himself,
and to have his loyal dark side adepts protect him while he grew into a full adult.
With no other options left, Palpatine agreed and began to make preparations.
When the time came, he confronted the Solos with their newborn and attempted to kidnap
him.
But they, with the help of Luke and a few other Jedi, were able to prevent this.
During the struggle, Palpatine was shot and killed by Han Solo, forcing the sith lord
to release his spirit from his body.
With a last ditch attempt to come back to life, Palpatine moved his spirit towards Anakin
Solo, but was blocked when Jedi Knight Brand sacrificed himself and forced the spirit into
his own body.
Having Palpatine’s spirit within him, the darkness itself ate away Brand’s body, causing
him to die shortly after.
When he died, he was able to force Palpatine's spirit to be captured by every other Jedi
who had become one with the force when they died.
They all kept Palpatine’s spirit in a prison and never allowed him to resurrect himself
back ever again.
And that’s how Palpatine’s story ended in Star Wars Legends.