WARNING: The following contains spoilers for Demon Slayer: Kimetsu no Yaiba Season 2, Episode 12, "Things Are Gonna Get Real Flashy!!," now streaming on Funimation, Hulu and Crunchyroll.
The first phase of Tengen Uzui's mission in Demon Slayer: Kimetsu no Yaiba's "Entertainment District" arc is complete now that he has been reunited with all three of his wives. His original plan -- sending Suma, Makio and Hinatsuru undercover as prostitutes in the city -- backfired spectacularly when all three vanished. When Tanjiro, Inosuke and Zenitsu were dispatched, only for Zenitsu to disappear as well, the Sound Hashira realized that his concern for his wives had clouded his judgment. Freshly reunited with all three, Tengen appears ready for phase two of his new plan: killing the demon.
Tengen stumbles upon Hinatsuru pretty quickly at the beginning of the episode, finding his wife tied up in Daki's notorious kimono belt and on the verge of death. As all of his wives are fellow shinobi, Hinatsuru decided to poison herself in an attempt to escape and alert Tengen about the demon. However, she was captured all the same by a kimono belt that Daki had given her as a gift, not knowing that it was a trap. After giving her the antidote to the poison, Tengen thanks her for her good work and orders her to leave the city.
Meanwhile, Inosuke locates Tengen's two remaining wives, Makio and Suma, by (disgustingly) dislocating all of his joints and slithering through a tiny hole beneath Ogimoto House and entering Daki's "food locker." After freeing Makio, Suma and Zenitsu -- who was also trapped down there -- the four of them battle a belt-shaped demon who guards Daki's food. As they begin to realize the fruitlessness of battling a demon while surrounded by food for that demon, fortunately, the sounds of their fighting draw Tengen's attention from the surface.
After the Sound Hashira quite literally bursts onto the scene, he quickly disposes of the belt demon and frees all the people who had been trapped by Daki's strange power. Pleased to see his last two wives mostly unharmed, Tengen becomes his flashy self once more as Suma and Makio are brought to tears by their husband coming to their rescue. As Tengen celebrates finding his wives by twirling his impressive blades around and announcing things are about to get flashy, there's only one thing left on his to-do list: kill Daki.
Tengen is worlds above Tanjiro in strength, so the fact that Daki is currently just shy of actually struggling against Tanjiro doesn't bode well for her chances against a Hashira -- and a vengeful Hashira at that, considering how Tengen likely feels about the fact that Daki dared to abduct and harm his wives. A flashback in the food locker reveals that Tengen's wives are the most important thing in the world to him. He even orders them to go against their shinobi training by always putting their own survival first, even above the survival of the people they ought to be protecting.
Tengen Uzui's Sound-Breathing finally made its brief debut in the anime when he uses it to blast his way into Daki's underground lair. That the resulting explosion from a single move with his massive blades can be heard across the city and allows him to tunnel deep under the earth is impressive. Tengen's brute strength alone might be more of an issue for Daki than Tanjiro's Hinokami Kagura. The Sound Hashira no longer has any reason to be kept out of the fight against Daki, so Demon Slayer appears to be barreling toward the final showdown with Upper-Rank Six of the Twelve Kizuki.