Warning: the following contains SPOILERS for Ozark season 4 part 1.
Ozark's new big bad villain Javi Elizondro (Alfonso Herrera) may not be likable, but he is the villain that the Byrdes and Ozark's audiences deserve. Indeed, the unpredictable and pretentious Javi does a great job of being annoying – far from the calm and cool personality of Omar Navarro (Felix Solis), whom Javi replaced as the new head of the Navarro cartel. Ozark season 4's villain definitely rubs everyone the wrong way – and that's the point.
Ozark season 4 part 1 sees Omar Navarro, the former main antagonist, becoming more of a colleague than a threat to the Byrdes, a notable transformation from his terrifying mystery and intimidating presence in previous seasons. After the Byrdes essentially figure out the puzzle that is dealing with Omar, they're immediately met with the obstacle of Javi, whose way of playing the game has caught the Byrdes and everyone else involved in the business off-guard. Apart from openly threatening Marty (Jason Bateman) and Wendy's (Laura Linney) lives, Javi even attempts to flirt with Charlotte (Sofia Hublitz) as a way of showing his dominance. Moreover, as his last act of Ozark season 4 part 1, Javi unceremoniously executes Darlene Snell (Lisa Emery) and Wyatt Langmore (Charlie Tahan), inadvertently earning the ire of Ruth (Julia Garner) in the process.
Ozark's introduction of Javi violently throws a wrench into the Navarro cartel and the Byrde's well-oiled heroin distribution and money laundering machine – a reminder to everyone that however far they climb up the criminal ladder, there will always be confidently incompetent power-hungry players to complicate matters. Javi's knack for random violence also undermines the Byrdes' idea to gather enough money or capital to become “too big to fail,” as Javi can simply shoot them himself whenever he feels like it and ignore the consequences. Javi may not be the villain that Ozark fans want, but he's definitely the villain that the Byrdes deserve. While Omar falls closer to the idea of the calm, cool, and cunning criminal mastermind as popularized by the antihero genre, Javi upends all these expectations in Ozark season 4 part 1 – a stark reminder to the Byrdes, and Ozark's viewers, that drug lords are also just terrible, despicable people.
In fact, even the FBI didn't want to work with Javi after their deal with Omar fell apart. Just like the Byrdes and Omar, the FBI is simply being forced to deal with the results of their own actions. Despite the fact that Javi's leadership could compromise the Navarro cartel, the unpredictability that Javi brings to the table isn't nearly enough to offset his worth to the FBI as an informant. The results of the FBI's poor choices will further unravel in Ozark season 4 part 2, as Javi is bound to cause problems while doing his own version of upholding his end of the deal.
Ozark's Javi Elizondro is a hurricane that was designed to make life much more difficult for the Byrdes, Ruth, the Navarro cartel, and the FBI. Even if Javi gets outsmarted by the Byrdes or killed by Ruth, Javi's fall is bound to come at a terrible price. While the Byrdes survive through intricate planning, Javi just does the next thing that comes to his mind, which makes him the perfect villain for Ozark's upcoming final 7 episodes.