Episode 29 (Hanyō no Yashahime)

The Girl Named Rion is the twenty-ninth episode of Hanyō no Yashahime, and the 5th episode of the second season titled "The Second Act."

Summary
The Half-Demon Princesses befriend Rion, the only child of Beast King Kirinmaru of the Dawn, who had perished six centuries previously but had her spiritual essence perpetually bound to the earthly plane by the deep obsessive fatherly love Kirinmaru still has for her.

With her own strength and resolve to put a stop her father's ambition to bring forth the Degenerate Age foretold by the Sacred Tree of Ages itself, Rion is able to sustain her mind and enduring spirit within an artificial physical form and presents Towa with the universally ancient Star-Slicer Flute that transforms into the supremely powerful star sword the Zanseiken! With a universally powerful demonic weapon equal in strength to the Bakuseiken wielded by Kirinmaru, the Half-Demon Princesses are ready to face anyone or anything either Kirinmaru or Zero send their way.

Plot
Rion continues her friendship with the Half-Demon Princesses. Riku is nearby slaying thousands of small fly-demons. She says she lost her life 600 years ago. Kirinmaru has been overprotective of her ever since. He, as most daiyōkai, sent his child away to safety. Rion considers it a prison sentence and never approved of Kirinmaru's quest for world domination. He used a Dream Butterfly to keep her asleep and to communicate with her when they are asleep. There is also a that holds the curse together. Setsuna is recruited to break the thread and destroys Rion's Dream Butterfly. Kirinmaru drags Rion back to safety, but she reclaims her body and frees herself from him. With the barrier subdued, she tells Towa to use Kyūyōkon Root which transforms to the Star-Slicer Flute. It transforms again to be Zanseiken which she uses to slay the monsters and needs to again in order to match Kirinmaru and his Bakuseiken. Sesshōmaru, who has been following them, asks about Setsuna's skill level in her newly upgraded and supremely powerful naginata.

After expressing her wish to save her mother, Sesshōmaru destroys Setsuna's Dream Butterfly. He asks Moroha if she had encountered her father Inuyasha and leaves, not answering her question as to how he knows about her father's incarceration. Riku has also been following them and meets Rion. He tells them that Kirinmaru can access Riku's senses and warns them to get away. Thus, Towa approaches Riku and shouts through him to warn Kirinmaru that they are not afraid of him. Riku drives Rion to his place and promises they will meet again. Setsuna instantly collapses and begins to fall asleep for the first time in a decade. She finds it very annoying as she does not have much time to save Rin's life from Zero's fatal curse.

Trivia

 * The way Rion rises again with a body made of bones and grave soil is the same way the spiritless Kikyō did when she was forced to return to life.
 * After Setsuna cuts the red thread of destiny between Rion and Kirinmaru to cut Rion's Dream Butterfly, she saw the Dream Butterfly out of her for the first time since Towa saw it in "Secret of the Rainbow Pearls", and "Wielding the Tenseiga".
 * Setsuna's ability to sleep finally returns after Sesshōmaru cuts the Dream Butterfly with Tenseiga. However, as a result, the silver-scale curse cast upon Rin by Zero starts up again.
 * Towa has been shown to know how to play the flute, which transforms into the almighty Zanseiken, the opposing demonic, stellar sword that is equal to the one wielded by Kirinmaru, the Bakuseiken, which he had used to destroy the Grim Comet's fragment with his incredibly strong Blasting Barrage attack and had fought Beast King Tōga of the West, and eventually the Half-Demon Princesses with several times.
 * Sesshōmaru speaks to his half-niece and calls her by her name for the very first time; mentioning whether she had seen Inuyasha, his younger half-brother and her father, as well. He does not answer her question as to how he knows of her half dog-demon father's imprisonment in the Demon Graveyard.
 * The between Kirinmaru and his daughter Rion is shown to have been connected by several threads; whereas Towa and Setsuna's young human mother Rin's is linked to Zero by just one.
 * This marks the first time Towa announces the name of her strengthened and evolved dragon-based demonic attack she inherited from Sesshōmaru, and that Kirinmaru himself suggested; Twin Azure Dragon Wave.

Error

 * Among the places Kirinmaru and Rion flew above is which, however, should not have been there back then as it was built during the 17th century.