The Darksaber, the legendary lightsaber at the heart of The Mandalorian, may have a secret weakness - one known to Palpatine and Darth Maul. Introduced in Star Wars: The Clone Wars, the Darksaber was forged long ago by the Mandalorian-Jedi Tarre Vizsla. It became the Mandalorians' ancestral blade of leadership, passing from one leader to another. It has now found its way to Din Djarin, who had no idea what it signified when he unwittingly came into possession of the Darksaber.
According to lore, the rightful owner of the Darksaber wins it by combat. In Star Wars: The Clone Wars, the Darksaber was originally wielded by the Death Watch's leader Pre Vizsla. His alliance with Darth Maul and his Shadow Collective ended poorly for the Mandalorians, with a Darksaber duel between Vizsla and Maul in which the former Sith Apprentice triumphed. Maul claimed authority over Mandalore, by right of possessing the Darksaber. Curiously, though, Maul's own time with the Darksaber hints the weapon may be more limited than many believe.
Both Palpatine & Darth Maul Chose Not To Use The Darksaber
Surprisingly, Darth Maul only used the Darksaber a handful of times. After killing Vizsla, he then used it to murder Duchess Satine Kryze. He then went on to use his original lightsaber when he dueled Palpatine, however, only drawing the Darksaber as a last resort after Palpatine killed his brother Savage. Although Maul would eventually recover the Darksaber during the canon Son of Dathomir comic following his escape from Palpatine's prison, on his return to Mandalore he used a modified version of his classic lightsaber rather than the Darksaber. This was the blade Maul used against Ahsoka in Star Wars: The Clone Wars season 7.
Even stranger, Maul created a brand-new lightsaber made from an Inquisitor's blade in Star Wars Rebels show, keeping the Darksaber as nothing more than a trophy before Sabine Wren took it from his home on Dathomir. As such, Maul only ever used the blade performatively or in moments of great need and desperation. Even stranger, when Palpatine defeated Maul, he chose to leave the Darksaber on Mandalore - where it was recovered by Maul's loyalists. This is odd, because Palpatine - always power-hungry - could be expected to claim the unique blade for himself. Given the Darksaber is Star Wars' only black lightsaber, the Emperor would surely have understood it made him absolute ruler of another world.
What Did Palpatine & Maul Know (Or Learn) About The Darksaber?
It's been speculated that the Darksaber might lend itself to the Sith as a dark side weapon, especially if it carries an obsidian crystal matching the properties of the more traditional red kyber used by the Sith Lords. However, Maul and Palpatine's admittedly strange behavior surrounding the Darksaber implies they both knew something viewers currently don't. For some reason, they both considered the Darksaber a weapon they would rather not use - as though they were aware of a weakness. It's known the Darksaber requires its wielder to commit and embrace its power to be wielded effectively, so perhaps that level of submission can't be attained by a Sith Lord.
It's also possible that wielding the Darksaber was simply met with distaste by Maul and Palpatine as it was created by a Mandalorian-Jedi. At the very least Maul certainly seemed to value it more as a means to gain authority on Mandalore rather than an actual weapon during this era of the Star Wars timeline. Regardless, viewers will hopefully receive more clarity about the Darksaber when The Mandalorian season 3 begins streaming on March 1st.