WARNING: The following contains spoilers for Episode 36 of Yashahime: Princess Half-Demon, "A Place (Not) for Towa," now streaming on Crunchyroll, Funimation, Animelab, and Hulu.
When Towa gets kidnapped by Zero while she's vulnerable -- and without demon powers during the new moon -- she's forced to recall unpleasant memories that remind her of her biggest regrets in Yashahime. During her suffering, Nanahoshi absorbs her pain and sadness into his miniature galaxy so it will produce a rare and powerful fragrance. However, Towa's sorrow quickly turns into rage that unleashes her uncontrollable and violent demon powers, threatening both Zero and Rin's lives.
While Rin's Silver-Scale Curse continues to worsen within the Tree of Ages, she warns her husband that Towa is crying and in danger. Sesshōmaru listens to Rin's concerns and rushes to Setsuna and the Demon Slayers to warn her of Towa's condition. Meanwhile, Zero and Nanahoshi take advantage of the weak and powerless Towa, torturing her by using Nanahoshi's Dance of Grief, which shows her unpleasant visions and memories of her childhood.
Zero tells Towa that simply killing her wouldn't appease her or alleviate her grudge against Sesshōmaru's family. Given her spitefulness, Zero admits she wants the half-demon twins to experience regret and humiliation that exceeds what she was forced to endure in the past.
With the use of the Silver Pearl that was once embedded in Towa's eye, Zero recreates the tragic memories Towa tried hard to suppress. The first is the one that haunts her the most: when she was forced to let go of Setsuna's hand in the forest as it burned to the ground, which resulted in their separation for many years. This memory leads her to the moment she was found and taken in by the Higurashis, who help her look for her sister. When they finally came to terms with the fact Setsuna was gone, they stopped searching for her and continued with their lives. However, Towa never stopped thinking and talking about her lost sister, which causes her to get bullied by classmates who claim Setsuna was never real.
Despite Zero's torture, Towa refuses to cry or give them the satisfaction of her pain -- which forces Nanahoshi to use his Eternity Bug to draw out the darkness and loneliness that Towa wasn't even consciously aware of before. Zero later uses the Gold Pearl -- once embedded in Setsuna's eye -- to show Towa her sister's memories of her childhood. When Towa realizes that her twin sister forgot all about her existence and lived happily without her, she finally gives in to her pain and begins to cry. As Towa's hatred grows, Riku and Rion suddenly show up just as the new moon disappears and Towa's demon power returns.
As Sesshōmaru successfully reaches Setsuna and sends her to the Tree of Ages to meet her mother, Towa succumbs to her fit of rage and her overwhelming demon power causes her to visibly transform. She grows fangs and longer hair accompanied by glowing red eyes, and a dark aura that mimics Sesshōmaru when he's overcome by anger. In Towa's blind rage and bloodlust, the spirit of her grandfather the Great Dog-Demon appears behind her before mercilessly killing Nanahoshi and his Eternity Bug. Without thinking, she tries to kill Zero before Riku is forced to jump in between them and remind Towa that Zero's life is still tied to her mother by a thread of fate. Towa seems unaffected by this information, willing to kill both Zero and her own mother in order to get revenge.
By the end Episode 36, Towa's still set to attack Zero despite her connection to Rin and the danger she puts her entire family in. Zero is amused by her rage and promises to send Towa to hell herself, which doesn't bode well for Sesshōmaru's family in future episodes. Viewers will have to continue tuning into Yashahime to see if Rin will die from the Silver-Scale Curse, or be saved by her powerful demon family.