Diablo is the main character of the anime How Not to Summon a Demon Lord, also known by its Japanese title Isekai Maou to Shoukan Shoujo no Dorei Majutsu. Voiced by Sakamoto Takuma, Diablo made his debut when the series premiered in July 2018. The story centers around this unique protagonist—originally a game-exclusive Demon King—who finds himself summoned into a real fantasy world by two young girls. Right from the start, Diablo becomes a central figure, and it’s easy to see why he quickly captures the audience’s attention.

Once transported, Diablo takes on the form of his in-game avatar, appearing as a strikingly powerful sorcerer whose magical prowess surpasses even the most renowned mages in this new realm. His commanding presence, combined with his overwhelming strength and mysterious aura, makes him instantly stand out. People are drawn to him not just because of his abilities, but because of the way he carries himself—with confidence, authority, and an air of unpredictability. It’s no surprise that Diablo becomes the focal point of the narrative.

As the journey unfolds, Diablo gains popularity—not only among viewers but within the world of the story itself. Many female characters find themselves captivated by him, often expressing a desire to become his loyal servant or disciple. Along the way, he gathers a close-knit group of companions who support him through countless adventures. While he’s feared by many as the so-called Demon King, Diablo consistently reveals a more compassionate side, especially when it comes to those he considers allies or friends. This duality—his fearsome reputation versus his underlying kindness—adds depth to his character and keeps fans engaged.

There’s no denying that Diablo stands out as one of the most memorable figures in recent anime. His charisma, magical mastery, and leadership qualities have earned him a massive following. What really sets Diablo apart is how he blends raw power with emotional intelligence, using his knowledge of both gaming mechanics and human nature to navigate complex situations. Whether he’s casting a devastating spell or offering quiet support to a struggling friend, Diablo remains a compelling and relatable protagonist.

Now, when we look at personality types, Diablo fits quite well into the ISTP category according to the MBTI framework. He tends to be quiet, observant, and highly focused on the present moment. Rather than rushing into decisions, Diablo thinks things through carefully, relying on logic and practicality. He often prefers working alone, using his sharp analytical skills to solve problems efficiently. His expertise in magic and combat showcases his mastery in his field, while his reserved demeanor hides a deep sense of loyalty. When danger threatens his companions, Diablo doesn’t hesitate to step in—proving that beneath his calm exterior lies a fiercely protective nature. So yes, the ISTP label seems like a solid match for Diablo’s overall approach to life and challenges.

Beyond MBTI, there’s also strong evidence suggesting Diablo aligns with Enneagram Type 8—the Challenger. This type thrives on control, independence, and strength, all of which resonate deeply with Diablo’s personality. He’s self-assured, assertive, and unafraid to take charge, even in high-pressure situations. At times, his confidence can come off as aggressive or overly dominant, but it stems from a place of wanting to protect what matters to him. Justice and fairness are important to Diablo, and he won’t back down if he senses injustice—even if it means going against authority figures or established rules. These traits highlight the core motivations of an Enneagram 8: power, protection, and integrity.

In the end, while personality typing isn’t an exact science, both ISTP and Enneagram Type 8 offer insightful perspectives into who Diablo truly is. From his strategic thinking and independent streak to his unwavering loyalty and strong moral compass, Diablo embodies a complex blend of strength and sensitivity. And honestly, that’s part of what makes him such a fascinating character. Whether you’re watching him unleash a forbidden spell or quietly support a friend in need, Diablo continues to leave a lasting impression. All in all, Diablo from How Not to Summon a Demon Lord remains a standout protagonist whose journey, growth, and personality continue to resonate with fans across the globe.