Darth Vader doesn’t show up in Star Wars lightly. The key figure in George Lucas ‘ six-film Star Wars saga has already had quite the run but, in the years since, has been deployed only in very key instances. He fought his apprentice on Star Wars Rebels . He massacred rebels in Rogue One . He even gives Cal Kestis a good scare in a few video games. This week, Vader returned with maybe his most brutal moment yet, and Lucasfilm president Dave Filoni explained the cold, calculated reasoning behind it. Vader appears in the final two episodes of the latest Star Wars animated show, Maul: Shadow Lord. He’s deployed to help his Inquisitors capture not just a pair of rogue Jedi but also the former apprentice of his master, Darth Sidious. The result is basically a 30-minute-long fight scene as Maul, Jedi Master Eeko-Dio Daki, and apprentice Devon Izara desperately try to defeat the Dark Lord of the Sith. They fail and face dire circumstances all around.…