The final season of Better Call Saul must sadly show the full transformation of the once lovable Jimmy McGill into the slimy and conniving Saul Goodman, the man who assists Gus Fring and Walter White in expanding their violent drug empires across the US and then the world. Much like Breaking Bad, it's a show all about villains and the idea of being a villain.
Fittingly, each show has some of the most iconic villains seen in modern popular culture, with a number of the most dangerous villains from Breaking Bad returning for the prequel. From raging monsters to masterminds who cut with words, Better Call Saul is filled with a rich ecosystem of villains who all show different levels of intelligence.
Tuco Salamanca
Though an infamous criminal and the iron fist of the cartel's operations in Albuquerque, Tuco Salamanca is entirely unpredictable and deeply unstable. His violent outbursts can be targeted at just about anyone for just about any reason, often resulting in cold-blooded murder on Tuco's part.
All of the Salamancas seen in Breaking Bad and Better Call Saul are clearly quick to anger and driven entirely by the emotion when they feel it. Tuco is the prime example of this, a fact that isn't helped by his frequent misinterpretation of events around him and the intentions of others.
Betsy Kettleman
The faithful wife of disgraced former Bernalillo County treasurer Craig Kettleman, who was caught embezzling over a million dollars of public funds, Betsy is an early thorn in Jimmy's side in the show thanks to the absolute control that she exercises over Craig as Jimmy competes to represent him.
Betsy is incredibly unlikable. She's both waspy and waspish; an elitist who's completely unwilling to admit to any of her many wrongdoings. She, however, isn't anywhere near as smart as she likes to think that she is. With the help of Mike, Jimmy easily outmaneuvers her and gets the couple to finally accept a generous plea deal put together by Kim. Later, in season 6, the Kettlemans return to become pawns in Kim and Jimmy's plot to destroy Howard, with Kim obliterating what little remaining dignity the two had in a flash. It would almost be sad if it wasn't for Betsy and Craig's new scheme of stealing money from seniors through sticky-fingered tax services. Another ill-thought-out plan that was doomed to fail.
Marco and Leonel Salamanca
Almost never seen apart, Marco and Leonel Salamanca, often just referred to as "The Cousins", are the toughest muscle of the Salamanca family and maybe all of the cartel operations seen by the audience throughout either Better Call Saul or Breaking Bad. Though they mostly remain silent regardless of the situation, they don't exude much more intelligence than their close relatives.
The Cousins' most demonstrable intelligence is seen in their tactics in the heat of battle. They're both taken down by Hank when they attempt to kill him, but they're formidable enemies who show a clear skill for sneaking up on their prey and overpowering them through fearless shows of force. They're blunt but effective.
Hector Salamanca
To this day, when most fans of Breaking Bad and Better Call Saul think of Hector Salamanca, they think of his later years spent in a care home for the elderly. However, the feared cartel boss is shown to be a wily opponent in his old age, though this is often down to him being underestimated.
During the earlier seasons of Better Call Saul, viewers got to see a lot more of Hector when he was more directly in control of his side of the cartel business and he's much like fans expected him to be based on flashbacks in Breaking Bad. He's a detestable brute who rules through fear but he's incapable of truly fathoming the forces that are successfully working to destroy him, despite them being right at his side most of the time.
Don Eladio Vuente
Don Eladio is the head of the cartel operations that viewers see in Breaking Bad and Better Call Saul. Considering the conflicting personalities of Gus Fring and the Salamancas, he's clearly carved out a solid position of power in a highly volatile world, which requires some level of tact and at least a few leadership skills.
Eladio's own personality is shown to be loud and brash, intimidating his subordinates but in a more eloquent manner than Hector Salamanca. Though Eladio is also far more perceptive of threats than Hector, even waiting until Gus Fring drinks first from the bottle of tequila Fring gifted to him, he ultimately underestimates Fring's resolve and is poisoned by that same bottle of tequila in Breaking Bad.
Juan Bolsa
Juan Bolsa is shown to be effectively in charge of the cartel's operations north of the border in both Better Call Saul and Breaking Bad, answering only to Don Eladio. While he may be second in command at the most, he's the most well-spoken and level-headed of the established members of the cartel seen in each series.
One of Bolsa's most intelligent qualities is how he instinctively plays Eladio, the Salamancas, and Fring off of each other. Nevertheless, he's still taken out by Gus Fring in Breaking Bad, insisting that he'll have the last laugh right up until the moment he's caught off guard and shot dead.
Eduardo "Lalo" Salamanca
Of all the Salamancas seen in either Breaking Bad or Better Call Saul, Eduardo "Lalo" Salamanca is clearly the most charismatic and intelligent. Lalo is shown to be just as violent as his relatives but he's considerably more cold and calculating. Unlike Tuco and Hector, he's quick to see schemes going on around him and has so far survived one assassination attempt unscathed and successfully faked his own death, though not well enough to fully fool Gus Fring.
Lalo's ultimate fate is one of the unresolved plot points that season 6 of Better Call Saul needs to wrap up, though his characteristic temper is likely to blind him to whatever fitting fate no doubt awaits him in the later episodes of season 6.
Lydia Rodarte-Quayle
Lydia is another returning character from Breaking Bad, managing the legitimate-looking side of the meth manufacturing business that's funneled through the large conglomerate Madrigal Electromotive. She's clearly very good at her job, juggling her illegal enterprise with huge business concerns, and she's absolutely ruthless when it comes to the darkest and most violent aspects of the drug trade.
Though it keeps her alive in the face of a vengeful Mike and an indifferent Heisenberg in Breaking Bad, Lydia's fatal flaw is her cowardice, which leads to her having no real allies. After Gus Fring's death, she moves on to Heisenberg as a boss and then attempts to control everything by manipulating Todd. She's outsmarted and poisoned in the end by Walter White, finding out moments after Walt destroys Todd's operation. During the events of Better Call Saul, however, she's seen successfully building Gus Fring's empire and it's easy to see why he trusts in her intelligence.
Gustavo Fring
Gus Fring is one of TV history's greatest masterminds, outthinking and overpowering the cartel in Breaking Bad and carving out his own empire from mysterious yet humble origins in Chile. His arc in Better Call Saul shows the early stages of his plan to break free of the cartel and exact his revenge plan against them and it's as meticulously thought-out as fans had come to expect from the iconic villain.
One of the most impressive things that Gus Fring manages to pull off much more effectively than any other villain in either Breaking Bad or Better Call Saul is leading his double life. To most people, including the DEA, Fring is an upstanding pillar of the Albuquerque community, but he's secretly a murderous drug lord who will do anything to get what he wants. Sadly, in the end, what Gus truly wants is revenge, and it distracts him long enough for Walter White to get the upper hand and kill him.
Charles "Chuck" McGill
Though he's never violent, and he only ever bends the law at the very most to suit his needs, Charles Lindbergh McGill might very well be the most hatable villain of either Better Call Saul or Breaking Bad and he's certainly the most intelligent.
A respected lawyer dealing with severe and unusual mental health issues, Chuck uses his position of authority to do all that he can to sabotage the career of his younger brother, Jimmy, in order to prevent him from practicing law. It's in so doing that he truly betrays Jimmy's trust, getting Jimmy arrested and committing an act so wrong that even the bloodthirsty Salamancas would never do such a thing. Chuck's lack of emotional intelligence is his greatest flaw which, when combined with his razor-sharp mind, creates a loathsome villain who should really know better. Though he effectively tries to prevent his existence, does Chuck inadvertently create Saul Goodman and all the wrong that he does? It's a compelling question that the show has intelligently left unanswered.