Palpatine

Despite his frail appearance, Darth Sidious was in truth an incredibly talented fighter, with great expertise in lightsaber combat. Thanks to his tremendous skill, he killed Agen Kolar and Saesee Tiin — who were considered to be two of the finest Jedi of their time — each with a single blow, and while also engaged with Mace Windu, slew Kit Fisto moments later.[88] He also managed to fight Yoda to a draw in a lightsaber duel later on.[88] Many years later, Palpatine, in one of his clone bodies, engaged and defeated Luke Skywalker in a one-on-one lightsaber duel in his clone labs on Byss. He was ambidextrous and could change his fighting style at a whim — keeping his opponents unsure as to his next move. A master of every lightsaber combat form, Sidious drew his opponents in, fighting less than his true capability, and then striking the fatal blow when his opponents thought they had the better of him. When fighting at full strength the Sith Lord was a terrifying opponent.

Sidious claimed that he had grown stronger after returning from the dead. Considering that he may have spent time near becoming one with the Force, it's likely he wasn't exaggerating. His younger, fit, clone bodies would also contribute to his power.

In fact, the only people known to have defeated him in a lightsaber duel were Mace Windu on Coruscant[88], and Luke Skywalker aboard the Eclipse, but Skywalker had to be aided by his sister's Force harmony. lpatine was known to wield several lightsabers throughout his life. He had two during the time of the Jedi purge. His original lightsaber was kept contained within a neuranium statue of Sistros in his office, which he retrieved and used against Mace Windu and his Jedi backup. This lightsaber was lost when Palpatine was disarmed by Windu, falling out of his office window into the streets and alleys of Coruscant far below. He used a backup weapon against Yoda, this one machined out of a black alloy, though what happened to it is unknown. After being resurrected in a clone body, Palpatine had a collection of lightsabers taken from Jedi during the Great Jedi Purge which he used until his final death at the hands of Han Solo