At first? Nothing. The barrier the sorcerers erected around the area muffles outside sounds, but the curse(s) it(them)self(ves) must be doing something more, because it's not just quiet, it's... oppressive. Like warm, hot air surrounding them from all sides.

And then—the ground is gone. It falls apart, or shatters, or ceases, clearly not in a physical way, but in a way that means that the three of them are nevertheless in free fall.

Oh. Swamp. Buried underground. In retrospect, this was obvious.

She manages to make the land on one knee. In... horrible gross swampy muck water. Oh, ew. That is not fun to feel in tights. The fact that this is clearly a manifested domain and that this means that all muck and water made by it are made of curse energy that will eventually disappear is some comfort, but. Not very much. Ugh.

How did the others fare in this less than pleasant entrance?

Her allies are... not. Definitely not around, or visible, or anywhere near her. She can also neither feel nor hear them; only that oppressive, humid heat of the swamp and the chorus of a myriad unseen animals. It's dark, but somehow nevertheless illuminated, an eerie pale glow that comes from everywhere and nowhere, not so weak as to be useless, but also not so bright as to really give her a very good sense of the geometry of the place.

The place is a swamp, though, that one is for sure. The water rises to her ankles when she is standing, but the unmistakeable feeling of mulchy earth beneath her feet promises she can definitely sink deeper if she's not careful. There are vines and trees all around her, but it is not clear that they all actually connect to each other or the ground in a logical fashion. They could be better described as an impression of a swamp rather than a swamp.

Except for the mosquitoes. Those are definitely non-impressionistic mosquitos buzzing here and there and occasionally deciding to snack on her blood. Entirely non-supernatural, to the extent anything here is, but still loud and annoying.

Great. Perfect. Wonderful. She hates when curses have domains. Maybe it's sleeping, though. She doesn't have high hopes, three jujutsu sorcerers landing in its lair probably woke it up, but. There's always a chance.

She makes her way to what passes for high ground, here, keeping to open spaces as much as possible. Hayashi fully expects that she's about to be ambushed.

Is it really an ambush if she's expecting it?

Regardless of the answer to that deeply philosophical question, what happens next is almost out of a cartoon: vines wrapping around her feet and trying to pull her out and hold her upside down.

Not in this anime, asshole!

The vines get themselves some new piercings, and then she kicks her feet to break the now weakened vines that are pinned to what passes for ground, here. Okay, where's the curse responsible for this hentai bullshit, she was going to kill it anyway, but now she's going to extra kill it.

With her eyes it's not really that easy to make out but there's a concentration of cursed energy there that looks like a vine Pokémon of some kind.

Vine Pokémon gets to die! With great prejudice!

Any other takers for immediate death? And is there literally any sign of the boys, she kind of wants to go save them out of sheer principle.

No immediate sign of either more Pokémon or the boys. Some vines do disappear out of her way as the minor curse she exorcised starts dissolving into cursed energy and dissipating.

(She gives the dissipating vines a final kick, just so it knows she hates it.)

Ugh.

Yelling is unlikely to work, her vision here is garbage, and the environment is beholden to the whims of the curse that made it. Trying to find the boys is going to be a massive pain. It'd probably be faster to just find the damn curse responsible and - oh. Actually. She can just zero in on the biggest source of cursed energy and go kill it. It's the most obvious thing in this environment to a sorcerer's senses. This makes it the most obvious meeting point for three stranded sorcerers in a hostile domain. Fushiguro is probably realizing the same thing, or has already realized it. Itadori.... well. She hopes Itadori doesn't die.

Time to go hunting.

It's quiet for a while, and easy to locate the biggest source of cursed energy.

Until, that is, three curses of the vine Pokémon kind emerge from the water quite suddenly where they definitively had not previously been and try to grab her with more vines again.

The big one being asleep was definitely wishful thinking.

She unlocks the sheath to her fan's blade and lets it fly off to be lost in the muck while she dives for the nearest curse. To stab it, obviously. Yes, she could fuss with the vines, maybe play a little game of tag with the curses that can clearly teleport, or, she could start killing them and be done with this bullshit. The others will probably manage to get some kind of hold on her while she kills this one, but that's fine. They are not teenage boys that are both taller and stronger than she is. And if they pick her up, she can stab them too.

They're probably physically stronger than she is, regardless of not being taller or teenaged or boys. The one she's targeted makes a satisfying squelch sound as it dies, but the other two coordinate to try to firmly attach her to a tree by the arms and legs.

Hayashi snaps her legs together, drags her dominant hand with her fan over to her face, and then bites on the vine holding it. With cursed energy, of course. She's not an amateur. And then she can use the opening to slice her legs free so she can have purchase on the ground and drag the curse that's got her other arm over for a complimentary stabbing.

They try to add More Vines to the situation in case it solves anything—

—but that's when a fist bursts through the bark of the tree right next to her arm and grabs some of the vines holding her. "Awesome, that's a hit!" sounds Itadori's voice before his other hand, this one holding the cleaver, punches through the tree too and slices through rather a lot of vines for their trouble.

The way he doesn't seem to even nearly hit her suggests he probably knows what he's doing and isn't going at it blind.

Adding more vines does nothing about the fact that Hayashi Akiho is dragging this damn curse closer so she can kill it. It dies accordingly.

"Oh, hey!" she says brightly. Wait how the hell did he just punch through a tree? No, bad Hayashi, focus.

With the second curse dead, she can actually go back to being a ranged specialist, which she definitely is, she promises. Piercings for this annoying vine curse! Aiming for the center of mass.

It notices what's just happened to its twins and decides to try to flee.

But Itadori finishes trampling over the tree (what's on the other side of the tree? how was he there? Euclidean geometry seems to have decided to give up on giving sensible answers to these questions) and quickly leaps over to the other side of the curse, standing between it and the path it was taking to run.

The curse doesn't exactly stop, but it does hesitate for long enough for Hayashi's needles to hit it dead on and pierce it in whatever vital organs it has.

It is incredibly satisfying when curses realize that actually, the smart thing to do is run. Not that it usually helps. Now it has some cursed energy piercings! These do not immediately kill it, but she flares the residual cursed energy smoldering in them, and that manages it. She has a moment to let herself feel a little smug. Ha.

And then it's back to business.

"How did you punch through a tree?" she wonders, as the last curse present begins to dissipate.

"—hm? Oh. Mysterious superstrength of unspecified origin," he says, shrugging. "Always had it."

“That makes no sense, but. Okay. Do you have another inexplicable innate ability that let you come find me? That we can use to find Fushiguro-san, maybe?”

"I was following them," he says, hiking a thumb in the direction of the dissipating curses. "There were, like, six? I killed some, they started running away, then they disappeared but... I don't know, I just knew where to go. It was like following breadcrumbs. Mysterious invisible breadcrumbs you feel rather than see."