Jackie and Jade successfully recover the last Oni mask from the bottom of the ocean and get it to Section 13 before anyone can wear it. At first, it looks like the J-Team has completed their quest, having found all nine Oni masks. Just then, however, the nine masks magically crack and explode, and from out of their remains, Tarakudo's nine generals resurrect. With the Oni now able to carry out their master plan, the J-Team must make a final stand to stop Tarakudo and his generals once and for all, before the entire world is engulfed in eternal darkness.
Tropes:
- All Your Base Are Belong to Us: After being released, the Oni seize Section 13 and use it as their base for spreading their dark shroud.
- Big "NO!": Tarakudo yells this when he and his forces are trapped within his mask.
- Brought Down to Badass: Uncle's spell transforms Tarakudo into a full-body demon, which strips him of his telekinetic powers. Even without them, however, he is quite an able fighter, able to overwhelm Jackie, El Toro, and Viper.
- Call-Back:
- As Tohru said in the season premiere, the combined power of the nine generals can summon enough Shadowkhan to engulf the earth in eternal darkness. Upon being released, that is just what they begin to do.
- Jade volunteers to wear the Mark of Tarakudo and become Queen of the Shadowkhan again in order to find Tarakudo's mask in the Shadow Realm, but Jackie is against it. Tohru is the one who gets it instead, albeit reluctantly.
- The Cavalry: El Toro and Viper come to aid the J-Team when the Oni begin spreading their shroud of darkness.
- Chekhov's Gun: After the ninth mask is found, Jade believes the Hana Fuda cards aren't needed anymore. It then turns out they have one more aid to give: the revelation of a tenth mask...for Tarakudo.
- Crazy-Prepared: Uncle never leaves his shop without his magic socks.
- Dismantled Macguffin: Turns out there was a reason the masks were scattered across the world: bringing all nine together would free the demons trapped within, meaning that for once, the Gotta Catch Them All quest was a bad idea.
- Foreshadowing: When Jackie and Jade are recovering the ninth mask, Jade comments on how it seems too easy, since this was the last one that the bad guys would be making a final stand to get it. Turns out, Jade was right, as Tarakudo let them get the last mask, knowing bringing all nine together would free his generals.
- Got Volunteered: Uncle nominates Tohru to be the one to enter the Shadow Realm and retrieve the final mask. As he points out, with the fate of the world at stake, there was no better time for him to face his fear of Oni.
- Improvised Lockpick: After the J-Team is locked up in a cell, Viper tries to unlock the door with her hair to no avail. She then asks if anyone has a barber pin or a credit card. This leads to Jade sarcastically asking if the Hana Fuda cards will do and throwing them against the bars, which in turn leads to them revealing the existence of the tenth mask.
- Innocently Insensitive: Upon learning that there was a mask for Tarakudo, Jackie wonders how it was possible, as Tohru's research indicated there were only nine. Jade chimes in that maybe Tohru messed up that part too (referring to missing the part where the masks must never be brought together). Tohru groans and Face Palms in response.
- It Only Works Once: Jackie originally thought that gathering the spell ingredients that defeated the generals before was the only way to stop them, but Uncle points out that they weren't turned into masks, but imprisoned in masks, and since the masks were destroyed, the spells that originally defeated them won't work anymore.
- Near-Villain Victory: Tarakudo and his Oni came dangerously close to achieving their goal of engulfing the world in eternal darkness. It was only by chance that the J-Team learned the existence of one final Oni mask (meant for Tarakudo) that enabled them to win.
- Nice Job Breaking It, Hero: By gathering the nine masks together, the Chans end up releasing the generals inside them. Uncle lampshades by saying it was somehow Jackie's fault.
- The Night That Never Ends: Essentially what the Oni intended for Earth, by enveloping it in eternal darkness.
- Now You Tell Me: Due to a broken piece of the legend tablet being upside down, the J-Team missed the part where it warned gathering the nine masks together was a bad idea.
- Rule of Symbolism: Very meaningful that it's Jade, who once used Tarakudo's symbol back in Season 2 to summon the Shadowkhan, who ends up sealing the oni away for good.
- Sealed Evil in a Can: Tarakudo and his forces get sealed in the end, but this time, the Oni are all in a single mask.Jade: Cozy.
- The Reveal: It turns out that the ancient warriors who trapped Tarakudo's generals didn't make only nine masks; one was made for Tarakudo as well.
- Trail of Bread Crumbs: In order to bring Tohru back from the Shadow Realm after he retrieves Tarakudo's mask, Uncle ties a magic thread to his ankle.
- Villainous Breakdown: Upon discovering that the J-Team had obtained his mask, Tarakudo became enraged to the point that he vowed to destroy them all.
- Wham Shot: When Jade tosses the seemingly useless Hana Fuda cards into the wall, they activate despite the fact that all nine masks had been found, revealing the existence of a tenth mask...for Tarakudo.
- Xanatos Gambit: It turns out that Tarakudo was running one from the beginning: even if the masks were removed from their wearers, if all nine are gathered together, his generals would be released.
