"You hesitate because you’re weak. You don’t like to be weak, do you? Now, take this deck. Take it, and it will give you strength. In order to meet Kai again, you must get stronger."
-Suzugamori Ren, Ride 43: The Black Vanguard
Virtually none of the other antagonists in Cardfight!! Vanguard can really match up to Ren. Part of it is his stage presence, but more than that it’s the terrifying ease with which he manipulates and preys people’s feelings. While for the most part, Cardfight's narrative perspective is omniscient and we get every character's thoughts laid out to us, the perspective is severely limited with regards to Ren. The viewer is left completely in the dark about his goals up until very late in the first season, and that enhances the anxiety surrounding his schemes; for a kids' show, there are an alarming number of hospital scenes throughout the first season that we don’t see in the other two. The characters spend a lot of their twenty-six minute air time standing around in an infirmary staring at an unconscious Aichi. Kai’s flashbacks allude to Ren having gone through a similar scenario, so the fact that he’s willing to encourage Aichi to go down the same path and put him as well as his friends through that experience makes him fascinatingly cruel in a way that Leon and Void never quite reach. To Tetsu he’s a poisonous character who fully exploits his friend’s undying loyalty, to Aichi he’s a corrosive voice that leads him on a self-destructive quest for power, and to Asaka he’s a negative authority that uses her affection to control her, then throw her away when he’s done. Ren’s still doing all this with glowing, evil trading cards, but it’s the human drama that he creates which make him stand out over more ambitious villains that want to destroy the world.