After Disney's acquisition of both Marvel and Star Wars it was inevitable that Marvel would start publishing Star Wars comics at some point. Star Wars: Darth Vader is one of their first offerings. I have never thought Vader was a particularly interesting villain. If he is not threatening someone he just stands there breathing deeply and looking menacing. He has more personality than Sauron but less than Voldemort.
Without spoiling the story, the graphic novel picks up right after the events of the original Star Wars movie and before Empire Strikes Back. The destruction of the Death Star has shaken the Emperor's confidence in Vader and now Vader has to quickly strengthen his position before he finds himself replaced as the Emperor's right hand.