Mustard is a compelling villain from the widely popular anime series My Hero Academia, also known as Boku no Hero Academia. As one of the key antagonists during the first half of Season 2, Mustard quickly made a name for himself with his chilling demeanor and deadly abilities. He’s a member of the League of Villains—a radical faction bent on dismantling the hero-dominated society—and his presence adds a layer of intensity to the show’s darker arcs.

One of the things that makes Mustard stand out is his quirk: gas manipulation. This power allows him to generate and control toxic gases at will, making him a silent but deadly threat in battle. Not only can he incapacitate or kill his opponents with ease, but he can also track anyone who inhales his gas, giving him a serious edge in combat situations. It’s this combination of stealth, control, and lethality that makes Mustard such a dangerous foe.

But don’t be fooled—Mustard isn’t just brute force. While he’s certainly merciless and enjoys taunting his victims before eliminating them, he’s also surprisingly intelligent and strategic. He knows exactly how far his quirk can go and uses that knowledge to plan his moves carefully. In fact, he’s even gone so far as to modify his gas to make it more effective, showing a level of dedication and technical skill that sets him apart from other villains. His deep understanding of both hero and villain societies gives him insight into how systems work, which he exploits to further the League’s goals.

Fans of My Hero Academia often find themselves fascinated by Mustard—not because he’s likable, but because he’s complex. He’s brutal, yes, but there’s a method to his madness. That mix of cold logic, tactical thinking, and raw power makes him a memorable character. Mustard may be a villain, but he’s not one-dimensional. His calculated nature and self-reliance make him someone you can’t help but watch closely whenever he appears on screen.

When we look at personality types, Mustard fits the ISTP profile quite well. ISTPs are typically independent, hands-on problem solvers who rely on logic over emotion. And honestly, that describes Mustard perfectly. He’s quiet, keeps to himself, and only speaks when it serves a purpose. He doesn’t need a team to get things done—he observes, analyzes, and acts with precision. In high-pressure situations, he stays calm and thinks fast, adapting on the fly. These are all classic ISTP traits.

Emotionally, Mustard is pretty detached. He rarely shows any expression, maintaining a neutral, almost eerie calm throughout most of the series. This emotional restraint might seem cold or intimidating to others, but for Mustard, it’s just part of who he is. Like many ISTPs, he struggles with expressing feelings, choosing instead to focus on actions and results. It’s not that he doesn’t feel anything—it’s just that he doesn’t let emotions cloud his judgment.

Then there’s the Enneagram angle. Based on his behavior, Mustard likely falls into Type 6: “The Loyalist.” This type craves security and loyalty, often driven by fear of instability or betrayal. At first, Mustard was hesitant to fully commit to the League of Villains, showing signs of anxiety about where he truly belonged. But once he found a place among them, his loyalty became a defining trait—especially toward his own abilities. He takes pride in his quirk and relies on it heavily for protection and dominance.

However, that same loyalty can twist into paranoia under pressure. When Mustard feels threatened or doubts the trustworthiness of those around him, his behavior turns aggressive and destructive. That fear-based response is a hallmark of Type 6s when they’re pushed too far. So while his desire for safety and allegiance strengthens his resolve, it can also lead him down a dangerous path if left unchecked.

All in all, Mustard is more than just another villain in My Hero Academia. He’s a layered character whose actions are shaped by intelligence, strategy, and deep-seated psychological drives. Whether it’s through his terrifying quirk, his ISTP-like practicality, or his Enneagram Type 6 tendencies, Mustard leaves a lasting impression. And even though he fights on the wrong side, there’s no denying that he brings a unique kind of depth to the series. For fans who appreciate complexity in their antagonists, Mustard definitely stands out as one of the more intriguing figures in the show.