Kannagi, heir to the Teoti throne, leads his species' invasion of Earth, seeing humanity as an obstacle to Teoti survival. This drives his determined, manipulative personality and cunning strategies against the Shinkansen Ultra Evolution Institute. While usually composed, severe losses trigger intense reactions: Valtom murdering his father provokes restrained anger, while losing Abuto and the Dark Shinkalion causes a complete breakdown. This drives him to unleash the forbidden "Desperation of the Vanquished" power and personally enter the battlefield to eliminate Abuto.

After reabsorbing Tolerantia from the captured Valtom, Kannagi becomes entirely consumed by vengeance against the defecting Abuto, losing all reason. This single-minded pursuit continues until Abuto defeats him in direct combat. Recovering from the physical and psychological toll of the forbidden power, he undergoes substantial change. Overwhelmed by shame and regret for neglecting his people due to his obsession with the Dark Shinkalion's power, he abandons hostility towards humanity. Recognizing honor and dignity as core Teoti principles, he allies with the Shinkansen Ultra Evolution Institute. This alliance enables the Teoti to thrive on Earth and off-planet while achieving a long-standing ancestral goal: the permanent defeat of Arabaki.

During the final conflict against Arabaki, Kannagi, empowered by Arabaki's energy, battles Shin Arata and Abuto. Confronted by Abuto’s direct appeal, he is ultimately subdued. This encounter completes his transition into an ally, and he joins the combined effort to secure victory.