Why? And how would Enma get to the armory without Zoro carrying it because Zoro is not defeating King before that thing reaches the armory.
I don't think Zoro can continue fighting with Enma sucking his entire Haki like that
He will obviously run & search for Source of Sound while King chases him
Not only is Zoro famous for getting lost but also King's Attacks rely on great pushing power
So Zoro might end up at Basement
Zoro is definitely getting a Fire Sword cuz Usopp lied about it & Zoro expressed his wish to have one
And there is no better chance than a Fire Yokai to make that true, especially when Zoro have Hungry Swords & he is called Demon Slayer
When Zoro acquired Shusui, he said that it won't bend even if a Dinosaur steps on it
Not only is Zoro fighting a Dinosaur now but he will be unable to use Haki for the next few minutes due to Enma, & also can't use both his hands, so if King attacks him again, Zoro will have no choice but to block with Hakiless Sandai alone, which might break or at least crack
You bring up a good point, but I'm not convinced on how Zoro and Yokai meeting because of the location distance between the two. unless... King does a powerful move, crushing Zoro into the basement floors. Breaking Sandai
What about Yamato? Wouldn't she be the one to stop it from reaching the explosives? I mean thats one way for zoro and Yamato to meet, but there's the Nidai kitetsu; shouldn't Hitetsu be in the flower capital? If Sandai breaks, Zoro would need another sword, and dnt see him using Ama no habakiri.
As i said above, Zoro is known for getting Lost & King might push him there
Also it's a good area for Zoro to defeat King due to limited space, after all, Zoro complained about not being able to reach him in the Sky which is tiresome
It should also be noted that this Yokai seem to be Big Island Problem & yet Oda is moving quickly with it, in just couple Chapters, it's already almost in basement, and it definitely wasn't just added to give Yamato something to do (She actually was going to basement anyway, this Yokai is just an extra, so it must have another purpose)
Also Yamato already saw Yokai when it touched CP-0 Agents & yet she didn't stop it there, this Yokai is being reserved for someone else (Someone who recently learned to cut Fire & when he tries to do that, one of his Swords will absorb it to his surprise)
As for Second Oden Sword, yes it should be in Wano, but so should Hiyori, maybe she is carrying it.
And finally, a certain Interaction must happen to make Zoro find out King's Secret
So i think the interaction between King & Yokai (It will hit him, similar to how it hit CP-0) & how his Body reacts to it will make Zoro learn his Secret & Ability