WARNING: The following contains spoilers for Episode 18 of Yashahime: Princess Half-Demon, "Sesshomaru and Kirinmaru," now streaming on Crunchyroll, Funimation, Animelab and Hulu.
Sesshomaru has been a peripheral figure so far on Yashahime. Despite being the father of Setsuna and Towa as well as the one who imprisoned Inuyasha and Kagome, he's mostly stayed in the shadows. This ends in Episode 18, "Sesshomaru and Kirinmaru," where he returns to save his daughters from a foe too powerful for them to take out themselves.
The episode begins with the Princesses still stuck in the eight-fold trap. Konton is toying with Setsuna and Towa, who just can't seem to land a hit on him for whatever reason. However, Towa is able to use their hereditary ability to sniff out Konton's magic, and slashes through, destroying the trap -- and Konton with it. The aesthete peril is dead and beheaded, though unfortunately for Moroha, the head has gone up in smoke.
Riku is there to pick up Konton's Rainbow Pearl, revealing he is trying to collect all the Rainbow Pearls for himself and has no intention of giving them to anybody, even his supposed master Kirinmaru. Kirinmaru doesn't seem like the type of guy who'd take insubordination lightly, so while Riku has stayed one step ahead of the game so far, can he continue to do so?
The episode's highlight is the confrontation between Kirinmaru and the Princesses, in which it's revealed that Kirinmaru is behind the Dream Butterfly that stole Setsuna's ability to sleep. It's a mystery just what he wants it for, but Towa and Setsuna don't care that much. The Half-Demons pursue the fleeing Totetsu and, sure enough, come across his master. The fight that follows is extremely one-sided.
Usually, the Princesses struggle initially against a villain, but always come out on top. The fight against Kirinmaru is another thing entirely. Try as they might, the Princesses just can't touch him. All their strongest attacks are rebuffed, with even Moroha's transformation into Beniyasha only eliciting laughter from Kirinmaru. Towa's ability to absorb Demon energy doesn't work against Kirinmaru either. He easily deflects all her attacks, and even boasts about not having uses a single spell or skill during the fight with the three Half-Demons. Towa is only able to land a single hit on Kirinmaru, and this would have been the end for her if her father didn't show up.
At the last moment, Sesshomaru reveals himself and takes up his sword against Kirinmaru. Jaken states that Sesshomaru would never fight like this over personal reasons, but his motivations outside of protecting his daughters are murky. Either way, the fight is brutal and fast -- it's very clear just how much stronger these two are than our heroines. They fight to a stalemate, and Kirinmaru decides to retreat. Before he goes, however, he reminds Sesshomaru that they still need to work together. Sesshomaru then takes off as well, leaving his daughters and niece alone on the beach.
Episode 18 ends with the Half-Demon Princesses gathered at the Tree of Ages, trying to get its attention and getting nowhere. For now, the Dream Butterfly quest will have to be put on hold-- at least until they get stronger. Towa states that she wishes she knew what Sesshomaru was up to. It's hard not to feel the same way, especially given that Sesshomaru is still keeping a very important secret. Inside the Tree, Setsuna and Towa's mother is still sleeping. Whatever is going on here, it seems that Rin is at the heart of it -- but what part does she have to play?