Star Wars has revealed the Emperor's greatest superweapon; he turned a large part of Coruscant's undercity into a gigantic anti-Rebel processing center even before the two Death Stars were unleashed. The Sith have always been obsessed with superweapons; in Star Wars: The Clone Wars, Master Yoda noted that the edges of the Sith Empire's superweapons unleashed upon the Galaxy that he hoped never to see in his time.
Sadly, when Palpatine rose to power, he ushered in a new era of superweapons. The old Expanded Universe even mocked this in a memorable scene in which Han Solo suggested the Empire's superweapons always malfunctioned. He suggested that, in response to an alien invasion, the Empire would create a colossal superweapon of some sort, which would later by destroyed by some hotshot pilot because the Empire forgot to bolt down a metal plate. Han's quip may not be canon anymore, but the fact remains the Empire's superweapons were indeed ill-fated. Even the First Order's Starkiller Base only fired on Republic space once before being destroyed.
But Alexander Freed's novel Victory's Price reveals the Emperor's greatest superweapon - one constructed long before the Death Star - was actually a success. Palpatine had a massive databank constructed on Coruscant, stretching underneath the Imperial Palace all the way to the Verity District some miles away. This computer system catalogued everything done by every citizen of the Empire, from the most subtle act of corruption to the most horrific massacre. The Emperor had created a system where it was impossible to live without becoming complicit in some way, and he used this database to ensure he knew exactly how complicit every single person was.
The Emperor went one step further, though, using this database to choose who should rise through the ranks of his Empire. And he ultimately used it for diabolical purposes, because after his death in Return of the Jedi, he sent droids out across the galaxy to recruit Imperials who were truly loyal, and who would have no qualms about committing the most heinous acts of genocide. These Imperial loyalists were used to launch a horrific scorched-earth policy across the entire galaxy, burning entire worlds and civilizations to the ground. And the droids used the database on Coruscant to identify who would be receptive to these extreme commands. Operation Cinder, as this strategy was called, was the Emperor's ultimate superweapon - and it worked.
Let's face it, the Emperor's database is the ultimate superweapon for the 21st century, where knowledge has been weaponized by governments and corporations alike. Star Wars has always been representative of such topical issues; modern viewers tend to forget George Lucas was inspired by the Vietnam War, and the prequel trilogy was influenced by the politics of the late '90s and early 21st century, but this element was sadly missing from the sequel trilogy. It's exciting to see Star Wars regain that cultural edge, with a superweapon fit for the present day.
