Better Call Saul season 4 completed Jimmy's moral descent and his transformation closely mirrors that of Walter White in Breaking Bad. Premiering in the January of 2008, Breaking Bad went on to become one of the most critically revered television shows of all time but despite the gripping tension, crime thriller elements and witty black humor, Breaking Bad is a character study at its core. Delving into the mind of an ordinary man diagnosed with cancer, Breaking Bad charts Walter White's descent (or ascent, depending on your perspective) from a meek, frustrated high school teacher to the kingpin of a multi-million dollar drug empire. A spinoff, Better Call Saul, soon followed.
Similarly, Better Call Saul centers around the exploits of a single character - Walt's crooked lawyer, Saul Goodman. Many Breaking Bad fans might've expected the prequel to be a comedic look at Saul's previous attempts to wrangle his criminal clients out of legal trouble, with no moral depths the attorney won't plumb to. In truth, Better Call Saul ultimately turned out to be every bit as rich and detailed as its predecessor and began by exploring Saul's real identity, Jimmy McGill. While viewers already know how Jimmy's life and career will pan out, the journey towards that point has been full of twists and surprises that most Breaking Bad fans could never have predicted and, as the spinoff has developed, the parallels between Jimmy and Walt have become ever more apparent.
In Breaking Bad, Walt's criminal behavior doesn't manifest as soon as he receives the Doctor's harrowing diagnosis; but rather through gradual exposure to increasingly more risky and illicit situations. When Walt garrotes the unfortunate Krazy 8 in season 1, his distress is palpable, despite acting entirely in self-defense. In season 3, Walt is able to run down rival dealers threatening Jesse, before calmly exiting his car and finishing them off with no break in composure. Finally, Breaking Bad season 5's Walt callously executes Lydia without losing a wink of sleep. Much like real-life criminals, every immoral act Walt is able to get away with and mentally process leads to a more severe crime further down the line.
Jimmy's progression is extremely similar. Unlike Walt, there has always been a dishonest side to Jimmy's personality but despite his history as a con artist, Jimmy in his youth demonstrated a kind heart and a desire to be better, leading to a fledgling career in law. Mirroring Walt's path, however, a series of events push Jimmy into increasingly murky territory. In season 1, most of Jimmy's cons are intended to fight back against massive rival law firm, HHM. By season 2, Jimmy is sabotaging his older brother, Chuck, to try and help Kim's career, inadvertently causing his brother's suicide. Finally, the Better Call Saul season 4 finale sees Jimmy emotionally manipulate the circumstances around Chuck's death to win back his law license and evidently feels no shame about doing so. As with Walt, each act of wrongdoing leads Jimmy towards something worse, going from mildly immoral to downright despicable.
Another similarity between Jimmy and Walt's respective arcs is how both men attempt to morally renege on their criminality, but eventually give in to the outlaw that they've become. Walt constantly attempts to justify his actions using his cancer diagnosis, the well-being of his family and the need to avoid going to jail, before finally admitting that he actually just enjoyed being someone of importance. Likewise, Jimmy repeatedly claims that his actions are intended to create a level playing field, or for Kim's benefit, or to correct a previous injustice. In the season 4 finale, however, Jimmy eventually seems to fully embrace his Saul Goodman persona.
This isn't to say that Breaking Bad and Better Call Saul are similar shows. Despite the natural crossover from one to the other, both series have distinct themes, tones and visual styles, but as Jimmy's transformation into Saul developed, it became clear that Walter White and Jimmy McGill have more in common than their Breaking Bad partnership might've suggested.
Better Call Saul season 5 is due to premiere in 2020.