Star Wars ‘ vast, interconnected galaxy can make cameo appearances a fraught endeavor . Fans who follow along want the intertextuality of the saga to matter, and appearances across stories can enrich both the story and the character making the cameo. On the other hand, in an era where  Star Wars has arguably leaned far too much on the familiar, they can feel like empty shocks , distractions that put the brakes on the narrative you were watching and make that vast galaxy feel frustratingly small. “Darth Vader shows up in the Darth Maul show” is a sentence that, even beyond a cynical reading, seems like it’s almost inevitable to fall into the latter—a meeting of two dark apprentices that sacrifices story for shock value. And yet, Vader’s appearance in  Shadow Lord strikes an almost perfect balance of spectacle and narrative heft that it strengthens both into one of  Star Wars ‘ most effective cameos in years.…