I will say Kassav looks a lot cooler than I imagined him reading LOTJ. I did the Psycho Mantis gas mask with a dress suit. Absolutely classy for a loutish pirate. And Zuckuss finally has his best friend back. I wonder if they bothered to salvage 4-LOM's old body from Nar Shaddaa before the mission. Or did they just slap his head on another protocol droid body?
I think that by "the rule", they meant the existence. In Legends, he was also recorded as the last Sith until 32 BBY, but in actuality, Zannah made someone lose their mind and make the Jedi believe it's Bane. If we follow the Jedi's idea, they may have thought he was reestablishing the Sith, but was "caught".