Reze from Chainsaw Man is frequently typed as ISFP in modern MBTI discussions, although some interpretations argue for ISTP because of her combat ability, composure, and practical thinking. When examined through the framework of Carl Jung's Chapter X of Psychological Types rather than modern personality stereotypes, ISFP emerges as the strongest four-letter equivalent. Since Reze is a fictional character and Jung never analyzed her, this assessment is an interpretation based on her consistent behavior throughout the series rather than a definitive psychological classification. The dominant function associated with the modern ISFP type is Introverted Feeling (Fi). Jung described the introverted feeling type as someone whose psychological life is governed by deeply personal values that often remain hidden beneath a calm or reserved exterior. Such individuals rarely express their emotions openly, yet their inner emotional experiences are exceptionally intense and authentic. Reze consistently demonstrates this pattern. Outwardly, she appears adaptable, charming, and emotionally composed, but beneath her carefully maintained persona lies a private emotional world shaped by loneliness, exploitation, and the longing for genuine freedom. Throughout her interactions with Denji, it becomes increasingly clear that her most significant internal conflicts revolve around personal feelings rather than ideology or duty. Jung observed that introverted feeling often conceals itself behind an outward appearance that others may misinterpret as emotional neutrality. Reze embodies this characteristic throughout her story. As a trained assassin, she expertly controls her emotional expression and fulfills dangerous missions without revealing her true thoughts. However, the gradual development of her relationship with Denji exposes an authentic emotional attachment that conflicts with her assigned role. Her growing hesitation demonstrates that her decisions are increasingly influenced by personal values instead of external expectations. This shift reflects the dominance of Introverted Feeling, where deeply held convictions eventually outweigh imposed obligations. The auxiliary function of ISFP is Extraverted Sensing (Se). Jung described the extraverted sensation type as someone fully engaged with immediate reality, responding instinctively and effectively to changing external conditions. Reze's combat style perfectly illustrates this function. She possesses extraordinary physical awareness, reacts instantly to threats, and adapts fluidly during battle. Rather than relying on elaborate long-term strategies, she excels through direct interaction with the present environment. Her movements are precise, efficient, and grounded in immediate perception. Outside combat, Reze also demonstrates healthy Extraverted Sensing through her ability to enjoy simple experiences despite her difficult life. Her conversations with Denji at the café, their shared moments by the school and swimming pool, and her appreciation for temporary freedom all reveal an individual capable of immersing herself completely in the present moment. Jung emphasized that sensation types often experience reality vividly and directly, and Reze consistently displays this quality whenever she briefly escapes the demands imposed upon her. The tertiary function of ISFP is Introverted Intuition (Ni). Jung described introverted intuition as perceiving hidden meanings, future implications, and symbolic possibilities beneath observable reality. Although not dominant in Reze, this function becomes visible during her growing awareness of the life she truly desires. As her relationship with Denji develops, she begins envisioning an alternative future beyond violence and manipulation. She gradually recognizes that both she and Denji have been treated as tools by powerful organizations, allowing her to perceive deeper patterns underlying their shared experiences. Jung noted that intuition often appears as symbolic insight rather than logical reasoning. Reze's growing realization that genuine freedom may be possible represents this function supporting her dominant feeling. Her decision near the conclusion of her story reflects an intuitive recognition of what her life could become if she followed her authentic values instead of remaining trapped by external control. The inferior function of ISFP is Extraverted Thinking (Te). Jung regarded the inferior function as the least conscious aspect of personality, often emerging awkwardly or under significant pressure. Reze demonstrates remarkable tactical competence, but her organizational abilities consistently serve external commands rather than personal leadership. She effectively carries out missions designed by others yet rarely seeks to impose systematic control herself. When forced to choose between completing her assignment and following her personal feelings, her objective efficiency gradually collapses beneath emotional conflict. This tension illustrates the relative weakness of Extraverted Thinking within her personality. Although capable of executing complex operations, she struggles to suppress her authentic values indefinitely. Her emotional commitments eventually override the detached efficiency required by her mission, demonstrating Jung's observation that the inferior function often becomes unstable when it conflicts with the dominant psychological orientation. Jung observed that introverted feeling types frequently appear mysterious because their deepest motivations remain concealed beneath restrained external behavior. Reze exemplifies this characteristic. Other characters, including Denji, initially perceive only the role she chooses to present. Her true personality gradually emerges through subtle emotional moments rather than dramatic confessions. Even when deception defines much of her behavior, genuine affection slowly becomes impossible to disguise completely. Her emotional sincerity exists beneath layers of self-control rather than replacing them. Some viewers identify Reze as an ISTP because of her calm demeanor, combat effectiveness, and adaptability. While these qualities certainly resemble dominant Extraverted Sensing supported by analytical thinking, Jung distinguished thinking from feeling according to the basis of judgment rather than observable competence. Reze's defining internal struggle is not between logical alternatives but between personal emotional values and external obligations. Her final decisions consistently arise from authentic emotional attachment instead of detached analysis, making dominant Introverted Feeling a stronger explanation than dominant Introverted Thinking. Others argue that she is an INFJ because of her quiet nature and apparent insight into Denji's emotions. However, Jung's intuitive type is fundamentally guided by symbolic perception and future-oriented vision. Reze's strengths consistently emerge through direct engagement with present reality and personal emotional authenticity rather than abstract intuition. Her awareness of deeper possibilities supports her decisions but does not replace her concrete responsiveness or emotionally grounded judgment. Viewed through the framework of Chapter X of Psychological Types, Reze most plausibly corresponds to the modern MBTI type ISFP. Her deeply private emotional values reflect dominant Introverted Feeling, her exceptional responsiveness to immediate reality demonstrates auxiliary Extraverted Sensing, her growing vision of personal freedom aligns with tertiary Introverted Intuition, and her difficulty maintaining detached objective control is consistent with inferior Extraverted Thinking. Although fictional characters cannot be typed with complete certainty, the ISFP interpretation provides the most coherent explanation of Reze's motivations, emotional conflict, and observable behavior according to Carl Jung's original theory presented in Chapter X of Psychological Types.