Mixed Martial Arts (MMA) has achieved substantial institutional maturity as a regulated global sport. However, its conceptual development continues to rely heavily on external disciplinary frameworks such as striking arts, wrestling, and Brazilian Jiu-Jitsu. This paper proposes a native taxonomy of MMA grounded in the internal logic of competitive interaction. The model distinguishes between structural zones of engagement and the functional layer comprising intentions, functional modes, and technical components, offering an integrated framework for describing how MMA action unfolds. The taxonomy emphasizes that fighter performance is shaped not only by disciplinary background but also by adaptive functional tendencies and context-specific roles. Empirical observations from elite competition illustrate the limitations of origin-based classifications and support an MMA-centered perspective. Rather than prescribing techniques, the framework provides a conceptual language for understanding MMA as an autonomous system. It also outlines potential implications for training organization, athlete development pathways, and governance-level curriculum design.