Emperor Palpatine - Martial Proficiencies & Weaponry (Legends)

For those of you who do not know, because nonStar Wars fans who don't know still exist, shockingly enough, Emperor Palpatine, a.k.a. Darth Sidious, is the primary antagonist of the Star Wars saga, portrayed in live action by the stage actor Ian McDiarmid, and by various voice actors in the tie-in media, examples including Nick Jameson, Ian Abercrombie, Sam Witwer, and Tim Curry.
This breakdown of Emperor Palpatine's martial proficiencies and weaponry was not drafted for a match-up, but instead as a dedicated profile of Darth Sidious' lightsaber skills, specifically in pre-Disney Legends material; I am not discussing Sheev Palpatine.
For this reason, I will be taking Palpatine's appearances in the 2008 Clone Wars animated series into account, as the series is still pre-Disney. Furthermore, Palpatine is the one established character who isn't done dirty by TCW, his appearances reflecting well on him and actually adding to what we know, as opposed to retconning and replacing the existing lore with an inferior copy, as is TCW's usual trend.
This breakdown of Emperor Palpatine's martial arts will be emphasizing his direct combat feats and training, and will be drawn from the following sources, listed in chronological order:
Darth Plagueis, The Wrath of Darth Maul, the TCW episodes The Lawless and Sacrifice, Darth Maul: Son of Dathomir, Revenge of the Sith, Dark Times: A Spark Remains, The Force Unleashed, Return of the Jedi, and Dark Empire.
Background information on the Star Wars setting will be drawn from the following:
The Complete Star Wars Encyclopedia, The Complete Visual Dictionary, Lightsabers: A Guide to Weapons of the Force, the Book of Sith, The Jedi Path, and the Jedi Academy Training Manual.
With all of that out of the way, let's begin.


Citations:
[03:09] - The Complete Visual Dictionary - Episode II: Attack of the Clones - Anakin Skywalker, Jedi Apprentice - Pg 82-83
[03:18], [03:59], [07:34] - Star Wars Insider 62 - Fightsaber: Jedi Lightsaber Combat (article) - Pg 20-37
[04:18], [04:25], [04:41], [07:49], [07:57], [08:02], [08:06], [08:11], [08:16], [08:20]. [08:33], [08:39], [08:46], [09:48], [09:56], [10:06] - Darth Plagueis
[07:20] - Labyrinth of Evil
[09:04], [09:09], [09:16], [09:21], [09:26], [09:30], [09:37], [09:41], [10:02] - The Wrath of Darth Maul
[12:59], [13:03] - Star Wars Episode III: Revenge of the Sith (Adult novelization)
[13:42], [19:11] - Star Wars Episode III: Revenge of the Sith (YA novelization)
[19:22] - Dark Lord: The Rise of Darth Vader