Gustavo Fring (Giancarlo Esposito) is undoubtedly one of the most notorious villains of the Better Call Saul and Breaking Bad universe. His line, "I investigate everyone with whom I do business. Which careful man wouldn't?" shows that he is unlike other villains in the series; he knows how to conduct a business carefully and does the necessary things to maintain that.
He is a one-of-a-kind villain — smart, calculated, and patient, but his cruelty and brutality don't go unnoticed. One of these unforgettable instances is when he instructs Mike Ehrmentraut (Jonathan Banks) to kill German engineer Werner Ziegler (Rainer Bock) or when he stops Hector Salamanca’s (Mark Margolis) treatment, so he would stay paralyzed and unable to speak — keeping him mentally and physically tormented without the ability to express it. The series would not be complete without the other villains despite Gus Fring's undeniable presence in Better Call Saul.
Don Hector Salamanca
Hector Salamanca is the right-hand man of Don Eladio (Steven Bauer), the leader of the Salamanca clan, and the arch-enemy of Gus Fring. As a ruthless drug kingpin, he is money and power-driven and grooms his nephews to follow his line of work in the criminal underworld to serve as his successors (and do the dirty deeds for him).
He is one of the antagonists of the first few seasons of Better Call Saul until he experiences a stroke that paralyzes him. Despite his limited mobility to move and inability to speak, he still holds power over the Salamanca family. His nephew Lalo Salamanca (Tony Dalton) regularly visits him in his nursing home and tells him what their next steps will be.
Ignacio “Nacho” Varga
Ignacio Varga (Michael Mando), otherwise known as Nacho, is a complex character the audience gets to know a little more than the others. He used to work for his father at a small upholstery shop to cover his criminal lifestyle, but also because his father, Manuel, is the only family he has. However, things quickly change when it becomes apparent to his father that his son is involved with the Cartel.
Nacho resorts to poisoning Don Hector once he finds out that they want to use his father’s store as a front, which successfully leads to his stroke and paralyzation. Unlike the rest of the Salamancas, he prefers Ehrmentraut’s more calm and less impulsive approach to business — this is what makes him different. However, despite having a somewhat good conscience, he chooses to lead a criminal lifestyle and never wants to settle for what he currently has; he always wants more.
Charles "Chuck" McGill
Charles “Chuck” McGill (Michael McKean) is not the villain who tortures people or steals civilian money; he is an entirely different type. Jimmy (Bob Odenkirk) has always looked up to his older brother Chuck and aspires to be like him someday, following in his footsteps as a lawyer. However, despite Jimmy's love towards Chuck, from accepting his condition of electromagnetism hypersensitivity to buying him newspapers from the only stall that provides them every morning, he never gets any love in return. Chuck resents Jimmy for being a conman and, for that reason, does not want to acknowledge him as a lawyer. But something that Chuck has never admitted is that he has always been envious of Jimmy’s charisma and ability to make people laugh.
Chuck is an embodiment of the law in that he is unforgiving of any mistakes. However, when it comes to Jimmy, he uses this belief almost as an excuse because he wants to see Jimmy punished for all his wrongdoings. Though the audience knows that Chuck is ultimately right and that Jimmy will eventually regress into ol' “Slippin’ Jimmy," no one deserves this kind of treatment from their sibling.
Lalo Salamanca
Unlike the rest of the Salamancas, Lalo is a more favored villain due to his charismatic and friendly nature. However, he uses his charm to trick people into thinking he is a good and trustworthy person. In reality, he is unpredictable and constantly keeps everyone on edge as no one can foresee what he will decide to do; he can change his mind at any given time.
The audience always feels a sense of uneasiness whenever he’s on-screen, but it makes the series all more exciting. The perfect example of this is shown in the latest season of Better Call Saul, where he seeks revenge for his family's assassination. No one knows what he's going to do next.
The Salamanca Twins
Leonel and Marco Salamanca (Daniel and Luis Moncada), simply known as The Twins, appear almost mechanical and robot-like, showing no emotion and only doing what they have to do for the sake of the Salamanca family. They show no remorse for anyone and kill as instructed - human lives don’t matter much to them.
As seen in Episode 4 of Season 4, which is arguably the series’ most violent sequence yet (almost like watching a Tarantino movie), the twins go after another Cartel clan (the Espinosas), guns blazing, killing over 20 people in a matter of minutes — like Terminators. They walked away with other people's blood-spattered all over their faces, clothes, and their skill-tipped cowboy boots.
Don Eladio
The audience doesn’t see much of Don Eladio, but they know that he holds all the money and power. Without him, Juan Bolsa (Javier Grajeda), the Salamancas, and Gus Fring would not be in any position of power. He might not directly kill with his own hands, but he instructs those below him to do these things to keep him and his business happy.
Don Eladio and Gus Fring have a history together. Eladio met Fring and his partner (and possible love interest) Max (James Martinez), who proposed a business deal on the production of methamphetamine, which Eladio did not like. He asked Hector Salamanca to execute Max right in front of Gus as he watched his partner’s blood drip into the pool. No wonder Gus hates him so much.
Mike Ehrmentraut
Many might disagree that Ehrmentraut can even be considered a villain, but he’s no angel himself. There’s no more drastic a transformation than a law-abiding police officer turning into crime boss Gustavo Fring’s right-hand man. He is a family man who seems to have a conscience but chooses to be on the wrong side.
His goal is to ultimately earn enough money for Stacey (Kerry Condon) and Kaylee (Abigail Zoe Lewis), so they can live a substantial life once he's gone but also to make amends for his son Matt’s death, whose death he holds a lot of guilt for. But because he chooses dangerous ways to earn his savings, he puts himself on the wrong side of the moral compass. A quote Ehrmentraut once said sums up his morality and how he does things, “I’ve known good criminals and bad cops, bad priests, and honorable thieves.”