While travellers are injured and recovering, Black Zetsu gathers his clones and divides the rest remaining to strike out at the weary travellers. There's not as many clones now, unable to create more with the tree born from Hashirama's cells burned and cut into firewood -still fuelling the bonfire in Uzu- but there's more than enough to cause a problem.
In the late evening, just as the sun begins to set, the scattered travellers are ambushed in the safehouses or at their temporary camps - none in Uzu or the major villages, but enough are mid-travel that this is going to be a bloodbath.
None of them see Black Zetsu, not through the wall of white bodies surrounding them.
Because instead, Zetsu goes after the weakest, intent on working his way through them all, crippling their already low numbers and leaving the strongest to burnout trying to do an army's job before he picks them off as well.
Zetsu goes after Copy Kitten.
Kakashi is sitting around a small campfire in the soaked marshlands near Kiri, body still faintly aching from half healed injuries - scabs still fresh and liable to reopen. He sits there, tired, staring off into nothing in particular and resting while he still can - before the next thing drags him in.
When he hears the sudden but quiet ripple of water, it takes him a moment to register it.
Kakashi turns and sees a White Zetsu watching him from the edges of the darkness, his small campfire too dim, casting shadows amongst the squat trees of the marshlands. Another peeks around a tree to the left, followed by one more standing on a branch.
Kakashi slowly rises as the area is surrounded.
Black Zetsu steps out last. "How do you know so much about mother?"
"Read it in a book," Kakashi says, tensing and relaxing his muscles to wake them up. "Icha Icha Playboy Bunny."
"You'll all die for this," Black Zetsu promises.
Kakashi slides his blank headband up. "Follow the plan, but stay wary of the black one."
Zetsu starts to frown.
A hoard of prodigy babies burst from the ground, ringing the Zetsu hoard. Zabuza thrusts his sword the size of a grown man into the air and roars. Dozens of tiny, high-pitched voices squeal along with him.
Kakashi takes point and leads the pack of murder kiddies he's befriended to swarm around the Zetsus' knees and engage a cradle formation. An inner circle dives straight for the Zetsu clones while an outer cage blocks any escaping Zetsu and tags in when tiny bodies get tired or immature chakra reserves drop too low.
Kakashi keeps his senses alert through the fight - kicks a few kids out of the way of trouble, shouts orders, but mainly distracts Black Zetsu because prodigies or not, they are still inexperienced and this is a struggle even while outnumbering the white clones.
Off in the distance, Yahiko summons a cloak of the Ichibi's chakra and grows a tail and claws. A little Yu girl shrieks, the sound amplifying out in a directed -if wobbly- cone, shattering squat salt trees and tearing a White Zetsu apart at the cellular level.
Kakashi's ninken are out in full force to assist, and also since a group of children wandering around is no small thing and the villages are bound to worry, this fight might get interrupted by a hunting group so at least someone needs to stay on watch while he is preoccupied with making sure none of his kiddies die an unfortunate and ill timed death.
Kakashi ducks a wayward kunai, readjusts a Kiri's poisonous fog, springs a trap on Black Zetsu and raikiris a White Zetsu.
Teamwork is essential, especially when one is young and really fucking weak all alone so Kakashi mainly focused this training on cooperation. Kakashi pulled these kids out only recently, trying to keep them from the mass slaughter that has now settled into an uneasy quiet, but Kakashi was only able to spend time with the group after he got reassigned.
A toddler Yamato stands in the ankle-high muddy water, wrestling back control of tree roots from the Zetsus because Orochimaru was able to recall the tests he'd done beforehand, so everything is turned up to eleven despite the shaky control. (Hashirama has practically adopted this boy ever since Orochimaru dropped him off. And Yamato certainly is stronger than last time, with a proper instructor at his side.)
Kakashi has been teaching these children how to cooperate and disregard village boundaries because maybe he's building an army. Seriously though, some poor Iwa kids thought that all Kiri have sharp teeth and eat children. It's obvious propaganda and easily disproved - in most cases.
Kakashi redirects a hail of shuriken away from a Kusa boy with his own kunai, launches Black Zetsu into the sky with an earth pillar, and then body switches with a Shimo just in time to duck swiping claws and spit out a fireball.
Oh, the travellers all knew that Zetsu would wait and strike at the best opportunity, so the stronger travellers out of Uzu acted maybe a bit more run down and ragged, spread themselves out just a bit too far, questionably left the little B-ranks alone in isolated areas. For an ancient being, Zetsu has spent so long manipulating people that he tends to underestimate his opponents - although, to be fair, they do know the future.
An Iwa girl doubles in size and beefs up (she basically grows into a normal adult woman) and blurs into a series of taijutsu attacks, slamming a White Zetsu backwards and into the path of a (future) Konoha ANBU's ninja wire.
It's just Kakashi's (shitty) luck that he got the boss instead of just the clones. So many hours of scouting missions wasted in an effort to find and eliminate traces of that weed when they could have just cast Kakashi out as bait.
Kakashi throws Gai away from the path of an oncoming jutsu, tackles down a Suna and yells out a warning for Mei. He then pulls up a wall only to slam it back into the ground as a Zetsu starts to tunnel underneath to try and grab him.
Kakashi is...a little bit unprepared for how chaotic this is getting and how much effort it is to be watching the entire battlefield at once, but this fight isn't going too bad actually, despite Kakashi saving his kids at the last second more times than he'd like to acknowledge.
One particularly small Kumo gets batted out of the air and he hits the ground, rolls a few times, and sits up in a daze. He looks down at his muddy clothes and the scrapes on him for a long moment before bursting into tears.
"Switch out!" Kakashi orders.
Shizune, from the outer line, helps drag the sniffling kid away and does a quick patch job on the skimmed knees and elbows.
A handful of White Zetsu are left when Kakashi orders the others back and refocuses on the Black Zetsu, that mainly only the Ame kids were distracting because Kakashi didn't want anyone else less experienced near that thing.
Kakashi's eye spins into the Mangekyo, to match Obito's artificially triggered pair from the hormone treatment he's been on, and Kakashi dives into the fight as the others retreat.
Kakashi locks Zetsu in a quick genjutsu just to stall for a moment and body switches with Mei for her to spit out lava, flips them back to dodge the lengthening arm grabbing for his throat, and misses his initial raikiri target but still manages to cut off Zetsu's arm before disappearing into the mist Zabuza prepared for him.
The kids are really good at listening to him, which makes training a lot more effective - very different from the other travellers whenever he has to train them. (Both groups are a step up from his previous genin.)
The Iwa children on the sidelines use earth jutsu to disturb the mayfly technique whenever the black leech tries to vanish through the ground, giving Kakashi just enough time to disable the thing and after Zetsu is pinned, Kakashi no longer needs to worry about the kids getting attacked so he really cuts loose.
After Zetsu is torn into enough pieces, and the rest of him looks like mush, Kakashi gives the signal and retreats.
"Throw it!" Yugito shrieks with panicked flailing of her hands, along with the bijuu cat tail behind her. "Throw it, throw it!"
Konan fumbles but pulls Isobu out of a pocket and hurls the fist-sized turtle. Children scream and run away as Isobu expands mid-air to the approximate size of the Hokage building, landing with the force of a small earthquake.
Isobu eats the remainder of Zetsu in one big mouthful, along with a giant crater of earth, and preps a bijuudama only to swallow it back down as a chaser for the tacky taste of Zetsu.
Everyone pauses.
Isobu waits for a brief moment, and then turns to Kakashi before opening his mouth. Kakashi and some of the braver children all cluster around Isobu and peek inside.
"I think it's dead," a Suna tries.
At this point, the S-rank Iwa Kazaru arrives after a dead sprint since Kakashi's ninken Bisuke ran off with a message to the nearest traveller when the fight started.
"You're late!" some of Kakashi's kiddies scream at the Iwa, very reminiscent of how Team 7 used to berate him.
"I hate everything about this," Kazaru deadpans, looking out over the kiddie cult, pointedly not getting close. "Who let this happen? Why did no one stop you?"
Kakashi shrugs. "On the bright side, Black Zetsu is dead, and the kids got in some real-world practice," he offers up to his fellow traveller.
And then Kakashi passes out.