WARNING: The following contains spoilers for Episode 20 of Yashahime: Princess Half-Demon, "The Hidden Village for Half Demons," now streaming on Crunchyroll, Funimation, Animelab and Hulu.
At this point in Yashahime: Princess Half-Demon, we have seen the origins of Towa and Moroha, and come to understand just what happened to Kagome and Inuyasha. But there's still one lingering mystery: just what was Setsuna doing in the time between her separation from Towa and her current life as a Demon Slayer?
Episode 20 begins with Towa following Setsuna around on patrol, as she recounts the story of her life. After a forest fire consumed their childhood home, the young Setsuna sat in place, paralyzed-- until Jaken arrived and whisked her away to her new home: Shiori's Village of Half-Demons. Inuyasha fans will recognize Shiori as the Half Human, Half Bat-Demon who was saved by Inuyasha and helped power up his Tessaiga. Now, as an adult, she is the leader of a village for Half-Demon orphans. Setsuna grows up here in relative peace, protected by Shiori's magic barriers and, all the time, receiving mysterious notes.
The notes are training instructions, furthering Setsuna's development as a warrior, and they imply something very interesting. Given that it was Jaken who took Setsuna to the Half-Demon Village, we can assume he was operating on Sesshomaru's orders. It's not too much of a stretch to infer the same thing about these notes. It seems that Sesshomaru wasn't quite the absentee father he first appeared to be and, even though he wasn't there to raise his daughter, he was still interested in her development. Sesshomaru probably knew that his presence would put Setsuna in danger, and so withdrew physically. But he still cared enough for him to try and give her tools to survive. And they'd turn out to be tools Setsuna would need very soon.
During the climactic fight with Gaga Gozen, Setsuna uses her powers in a way never seen before. She's indulged her Demonic form in the past, but the violence on display here is downright brutal. After Gaga Gozen arrives at Half-Demon Village, he initially seems like a tough opponent, with the young Setsuna struggling against him. Even Miroku struggles.
However, once Setsuna transforms into her fully demonic form, she makes short work of him. Some fans of Yashahime have complained about the lack of blood as compared to the original series, but there's plenty of gore here, as Setsuna literally tears Gozen into dozens of tiny pieces with her claws. It's shocking to see the typically controlled Setsuna lose control like this.
As the episode draws to a close, Miroku creates a seal to contain Setsuna's Demon power, preventing her from going berserk as she did here. Interestingly enough, the main tool he uses to cast the seal is Gozen's Naginata, which fans will recognize as Setsuna's signature weapon. Cutting a guy into pieces, then stealing his weapon? Even if he was a cannibalistic Demon, that's cold. Also worth noting is Miroku commenting on how Shiori grew up well, but not hitting on her. That's character development for you!
"The Hidden Village for Half-Demons" closes with Setsuna gently ribbing Towa about being a needy Half-Demon child, and then seeing off some demons from the outskirts of the Village. Setsuna is cold and reserved, but as we are learning, she has a strong heart deep inside. She still cares deeply about her adoptive family, and she is coming to care for her sister as well. As for Sesshomaru, he is still in the shadows, but it will be interesting to see what he has to say when he finally comes to meet his daughter's face to face.