Ep. 24: Nerval reveals missile truth while Leopard succumbs to Dark Leopard and declares war on humanity.

Xanthippe discloses that Nerval destroyed the missile and transported Imo-chan, prompting Akiha to attempt a rescue despite Kazane’s objections. Leopard engages in a dialogue with his alter ego, Dark Leopard, who urges him to rule humanity through fear as he once did. Awakened Imo-chan explains her actions and love for Akiha to Nerval, who shares his past mistake from 50 years ago and his desire to understand humans. After conferring with Aleida, Nerval seeks Benkei’s aid, but Tsutsuji’s refusal highlights his inability to fully comprehend humanity. Although Nami suggests he become a devil emperor, Nerval rejects this, seeking rational agreement instead. Meanwhile, Akiha and her friends disobey orders to rescue Nami, leading to a confrontation where Benkei attacks Leopard. Now fully controlled by Dark Leopard, Leopard retaliates violently, travels to Kirkwood, and declares himself the absolute ruler of humanity while destroying everything nearby. As Akiha’s group attempts to reach Leopard’s core, Nerval arrives to assist in stopping him.
Episodes
- Ep. 20 · Akiha Wakes in Box as Honoka's Lifespan Ends and Nami Is Stabbed
- Ep. 21 · Leopard searches for the Sword while Akiha escapes her box before UURE attacks Kirkwood.
- Ep. 22 · Akiha and Itsuki escape Nervalists while Honoka kidnaps Fon and the group rescues traumatized box humans from a disposal factory.
- Ep. 23 · Leopard completes with the sword while Akiha confronts her grief and enemies.
- Ep. 24 · Nerval reveals missile truth while Leopard succumbs to Dark Leopard and declares war on humanity.
- Ep. 25 · Nerval and Nami clash as Akiha discovers her destiny to end the brain colony wars.
- Ep. 26 · Kazane coordinates the assault on Leopard while Kagura confronts Nami and Xanthippe arrives to assist.