Ethan Roark Jr.

Roark Junior, also known as The Yellow Bastard, is the villain of the Sin City story "That Yellow Bastard". He is by far the most disgusting, vile villain in the entire series, which is saying a lot, and one of the most evil villains in all of fiction period.

Roark Junior, son of the extremely corrupt Senator Roark, is a sadistic serial killer pedophile rapist whose main hobby is murdering pre-pubescent girls. His father uses his extensive wealth and connections to let Junior get away with these atrocities. The law enforcement in Sin City is so throughly corrupt that Senator Roark himself got away with murdering his own wife with a baseball bat, even when he openly admitted to the crime. The story starts with Roark Junior kidnapping his fourth intended victim, 11-year old Nancy Callahan.

Detective John Hartigan, the hero of the story and the only good cop in Sin City, pursues the villain, defeats his minions, saves Nancy, and shoots off Junior's ear, hand and genitals. However, Hartigan's partner Bob turns on him and shoots him, because he knows Senator Roark would have them killed if they actually brought his son to justice. Hartigan is framed for Junior's crimes, and Senator Roark threatens to kill anyone he reveals the truth to. Meanwhile, the injured Roark Junior undergoes extensive reconstructive surgeries to repair his body and penis, but as a side effect he becomes hideously disfigured and has bright yellow skin. He continues his horrible killing spree, murdering dozens more innocent girls while Hartigan is in prison, and visits Hartigan in jail (not revealing his identity at the time), beats him up and gives him the severed finger of one of his victims, in the same kind of envelope Nancy had been sending letters to Hartigan in.

Realizing Nancy is in danger once again, Hartigan manages to gain parole after 8 years by openly confessing to the crimes he'd been falsely accused of and pleading for mercy at his hearing. He tracks down Nancy Callahan, who is now a stripper at a popular local bar, and is so far unharmed. When he sees the Yellow man who visited him in prison in the bar as well, Hartigan tells Nancy, who still remembers and loves him for saving her eight years ago, that she is in danger and has to come with him.

After they start driving away, the Yellow Bastard appears in a car behind them and tries to shoot them. Hartigan shoots back and hits the villain in the neck, causing him to spurt yellow blood. They stop to make sure he's dead, but find no body and decide to camp out in a nearby hotel. There, the Yellow Bastard ambushes them, ties up Hartigan with a noose and finally reveals that he is in fact Rourk Junior, and is now going to finally kill Nancy after all these years, and leaves Hartigan to hang to death. However, he manages to save himself by breaking off a piece of the window and cutting the noose with it, and goes to the Rourk family farm where Junior does his "dirty work" after interrogating the thugs hired to dispose of his body.

At the farm, the Yellow Bastard is whipping Nancy, who realizes that he's only satisfied if he hears his victims scream, which she refuses to do so. Soon after that Hartigan finally arrives at the farmhouse, only to keel over from his injuries. Junior starts moving in on Hartigan to finish him off, but before he can make the kill Hartigan pulls out a knife and stabs the Yellow Bastard's chest, then tears off his penis with his bare hands and beats him to death until his head is reduced to bloody yellow gibs.

Hartigan saves Nancy and tells her to flee, saying he will find a way to expose Senator Roark. However, once she is out of sight what Hartigan actually does is kill himself so Roark can't hurt Nancy to take revenge on him again.