Humming Fairy

Humming Fairy (ハミングフェーリー) is the ninth episode of Season 2 and the thirty-fourth of overall episode The Rising of the Shield Hero anime.

Synopsis
Naofumi’s party is teleported to Sikul, where Kizuna introduces the Vassal Weapon Hero, Ethnobalt. He says he can use a piece of Raphtalia’s hair and Naofumi’s blood as a catalyst that can create a shikigami to find her. He creates the shikigami, and they find…

Plot
Naofumi furiously demands Kizuna and Rishia to take them back, even if Kizuna insists to be a trap launched by Kyo against them, but Naofumi wants to ignore the risks just to return and help Raphtalia anyway. Kizuna notices the portal is closed at the other side. Naofumi suddenly feels the Wrath Shield's dark influence rising within. Kizuna mentions an ally of her who can track people and could help them find Raphtalia. She is soon greeted by her own people and notices they are indeed in Sikul, and asks them to bring someone or something named Ethnobalt. Somewhere else, a gruff-looking slave trader drags Filo and places her an enchantment which makes her reset back to her initial bird form, under the premise he'll make plenty of money the next day...

At Sikul's castle town, Kizuna explains how Naofumi's party helped her escape the Infinite Labyrinth. However, the people become uneasy around Naofumi upon knowing that he is a Cardinal Hero from another world, as they claim Naofumi came "to destroy their world", to which Rishia and Kizuna object. Naofumi grows angry (just like his first day at Melromarc after Bitch's false accusation) and feels the Wrath Shield's influence again. As he prepares to leave the castle, he sees a guy with silver hair atop a floating platform, who is formally introduced as Ethnobalt, the Boat Hero. He gives Kizuna a tarot-like card that was previously under Glass' care which transforms into Chris, a blue penguin-like shikigami who was created by Kizuna herself and Glass. Rishia asks how can a shikigami help them find someone, and Kizuna suggests Naofumi to create a shikigami of his own - by combining Naofumi's blood with Raphtalia's hair which he absorbed into his Shield when he gave her first haircut. As the shikigami creation ritual commences, the Shikigami Shield unlocks, and a cute creature is born, combining physical traits of both Naofumi and Raphtalia's child form. Kizuna explains that if the shikigami is alive and well, it means the person used as a catalyst to create it is still alive, much to the relief of everyone. Naofumi suddenly inquires if Ethnobalt is human, and he reveals his true form to be a white humanoid rabbit whose species has been protecting Kizuna's world for countless generations.

Kizuna explains she still cannot use Return Dragon Vein again, for it could transport them to some unknown place, so she suggests using Ethnobalt's Vassal Boat for transport. Outside the castle, Ethnobalt's floating platform expands and reveals to be the actual Boat Weapon, complete with a magic interface showing a hologram globe of the world. Chris and Naofumi's newly created shikigami show in the globe that Glass and Raphtalia are in the same place, and this is bad news as Kizuna mentions that "Raybul" is allied with Kazuki the "genius mage" and the same Mikakage people who imprisoned Kizuna in the Infinite Labyrinth. Ethnobalt explains his Boat can travel faster if it uses the Dragon Hourglass' portals, which is far better than Return Dragon Vein. Back at Mikakage, the slave trader is making money by cruelly exploiting Filo as a circus attraction. The Vassal Boat appears outside the town not to be detected by anyone. Naofumi notices Mikakage looks a little more "modern". As they walk, Kizuna asks Rishia about "Naofumi destroying the world", but before she can answer, Naofumi suddenly stops and starts running at the opposing direction, claiming to be hearing something...

Naofumi's guess was correct, as he soon reaches the slave trader where Filo (under the "humming fairy" motif) was being kept prisoner, and the audience feeling bad for her cruel treatment. The dangerous Wrath Shield suddenly materializes, symbolizing Naofumi's raging desire to kill the slave trader, but Rishia and Kizuna manage to calm him down and suggest waiting until nighttime and sneak into the tent to rescue Filo unharmed. They infiltrate into the tent, and soon find a room full of caged birds, one of them being Filo in her baby bird form surrounded by servant talismans to prevent her from contacting Naofumi. Filo herself uses her slave crest to break free from the talismans and Kizuna breaks the cage, effectively freeing her. As the slave trader comes by, Naofumi rapidly neutralizes him with his new Shikigami Shield, which entraps him in his worst nightmares just like he did to Filo. Sometime later, it is revealed the slave trader received Filo from his father, a local nobleman, and Naofumi speculates if it was Kyo who gave Filo to the nobleman. He also imagines that Filo has assigned a bird race native to this world, since filolials do not exist in this world, hinting her human transformation to be a unique ability of hers. Naofumi promises to never leave Filo again (just like he promised to Fitoria prior to this).

Next day, as they walk around, Filo gives the name "Raph-chan" to Naofumi's shikigami, much to the creature's joy. The town's notice board informs that "the wielder of the Vassal Katana has recently escaped and the town cannot find him yet". The Shield's interface shows that Raphtalia's stats had suddenly disappeared, but Raph-chan's presence means Raphtalia possibly is still alive, though in Kyo's hands, greatly concerning Naofumi.

In a snowy region somewhere, under a heavy blizzard, Raphtalia is taken as a prisoner to a mysterious castle atop a huge icy mountain.

Light Novel & Manga Differences

 * In the light novel and manga, Kizuna learned about Glass, L'Arc, and Therese attempting to destroy Raphtalia's World right after arriving into her home country. In the anime,
 * In the anime, it was hypothesized that Kyo captured Filo and gave her to the corrupt noble. This is the first time it was hypothesized - not mentioned in the light novel or anime.
 * In the light novel and manga, Naofumi names Raph-chan almost immediately. However, Filo names her in the anime.

Trivia

 * The shield Naofumi used to terrify the noble's son is the Nue Shield which has the "Night Terror" skill.
 * This episode has an after-credits scene.