Kakashi runs through the mass of oncoming white zetsus, cutting them down with his chidori. It is nearly exhausted, but he managed to take down at least a dozen. Finally, the jutsu runs out, and Kakashi backs up the stairs to survey the battlefield before he charges back in.
Rain appears beside Kakashi, throwing a dead white zetsu down the temple stairs. "Don't let them catch you," he advises. "They will drain your chakra."
"Right," nods Kakashi. "Anything else?"
"Don't let them get near Iruka's barrier. He can't hold it forever, and any attacks that hit the barrier will take away from the time he can sustain it for." Rain kicks another zetsu back down the stairs.
Kakashi surveys the battlefield, looking for an opening to jump back in. In the centre of the stairway Black Zetsu and Kurama's Guards fight their strange battle of countering each other's techniques. To the left and right of that battle, the Order of Jashin fights the white zetsu army. Between Kakashi and Black Zetsu, Wind is fighting off the hoards of white Zetsu that are slipping through the gaps between the defenders. Behind him Rain is protecting Iruka's barrier.
Kakashi leaps forward and attacks the hoards of zetsu slipping around the sides of the other fights. Kunai in hand, he helps Wind fight back the oncoming attackers. The zetsu are coming thicker and faster with every passing minute, and Kakashi is not sure he can hold out for the hours it will surely take for Madoka and Namiko to even reach the Hidden Leaf.
Seeing an opening, Kakashi starts weaving hand signs. "Water Dragon Jutsu!" he says, casting a jutsu he learned from a Mist Ninja. The jutsu sweeps away several zetsus, barely making a dent in the total number of attackers.
Wind is fighting with her hands encased in medical chakra, the kind used as a scalpel. She cuts through the zetsu like butter, killing dozens of them without batting an eyelash.
Kakashi casts an earth style jutsu that sends spikes up out of the ground, impaling several zetsu clones. As the spikes recede, Kakashi sees one of Kurama's guards fall, a wooden spike sticking out of his leg.
One of the other guards, Sei (if Kakashi remembers his name rightly), immediately stops fighting and hoists the fallen guard onto his shoulders. He carries his wounded comrade up the stairs and lays him down beside Iruka's barrier.
One of the Jashinists falls to the ground with a scream, and Sei rushes down the steps to pull her from the battlefield. Kakashi immediately jumps to Sei's defence as the zetsu clones try to cut him down before he can complete his mercy mission. Once Sei is safely at the top of the stairs with his patients, Rain extends his protection to them as well.
Kakashi and Wind notice an immediate increase in the amount of zetsu getting through the first line of defence. Kakashi erects a mud wall in front of himself and Wind in an attempt to slow down the attackers. Wind wipes out the rest of the zetsu on their side of the wall with a giant fireball similar to the ones the Uchiha clan uses. Kakashi wonders where she learned it.
For a brief moment, Wind, Rain and Kakashi have a chance to catch their breaths. They glance at each other. All three of them are a little out of breath. Wind and Rain clasp each others' hands for a second and nod.
"We can do this," says Wind, as if she is trying to convince herself more than anyone else. "We can do this," she repeats firmly.
A sound draws Kakashi's attention back to his mud wall. He turns in time to watch it collapse. A swarm of white zetsu bursts through, grinning as they advance.
Kakashi blasts them with a grand fireball, burning only a handful before the jutsu runs out of steam. He cannot afford to waste chakra sustaining a jutsu for too long. This fight could go on for days.
As soon as Kakashi's jutsu dies away, Wind sends in a water jutsu, calling it the Boiling Water jutsu. The steaming, bubbling torrent of water burns the oncoming zetsu. They fall back, but only for a moment. Soon they are swarming up the stairs again. Kakashi's sharingan tells him that jutsu is a normal water style jutsu, but the water is hot, rather than cold. He files it away for later.
Kakashi, his team and the Jashinists fight on. The zetsus do not stop coming. Long minutes pass in which several of the jashinists sustain minor injuries. Wind occasionally darts into the main battle and gives a little chakra to one of the Jashinists. Kakashi wonders if she should be doing that. Women usually have less chakra than men. However, Kakashi can sense huge amounts of chakra from Wind, chakra that is very slowly depleting as the fight drags on.
After some minutes have passed, another of Kurama's Guards falls. This one is dead, judging by the branches stuck in his neck and chest.
Kakashi feels a pang of sadness, but keeps fighting. There is nothing that can be done for the dead.
Slowly but surely, the defenders begin to see a definite lessening of white zetsu numbers. Kakashi feels an immense wave of relief wash over him as he realizes they might have a chance after all. He doubles his efforts, taking down dozens of white zetsu at a time. Wind and Rain fight steadily, taking out dozens of zetsu with each attack, but their attacks could not be more different. While Wind is flashy and bold, Rain simply dodges and then attacks. As far as Kakashi can tell, neither Wind nor Rain has been injured yet. Kakashi himself is not injured, his only problem is his depleting chakra reserves.
But, he thinks as the zetsu numbers dwindle away, the battle will be over soon. Feeling heartened, Kakashi fights on, as do his comrades.
And then, just as it seems the battle is nearly won, one of the last two Guards falls to the ground with a scream as Black Zetsu crushes her legs with an earth based jutsu.
The battle is not over yet. Kakashi starts to head in the direction of the fallen Guard, ready to carry her up the stairs to Sei. Wind is right beside him, cutting down the zetsus that try to stop Kakashi.
The ground begins to shake and rumble. The stairs break, and Kakashi and Wind are forced to stop. Dozens of white zetsu clones rise out of the ground, making a rocky mess out of the grand temple stairs. Rocks and dirt fly in all directions as an increasing number of the strange white monsters climbs out of the ground. Kakashi's heart sinks to his sandals.
The battle is far from over.
The white zetsus surround Wind and Kakashi, steadily advancing towards them. Kakashi and Wind stand back to back, turning slowly to keep a sharp eye on the newcomers.
Kakashi feels Wind touch his hand. A warm flood of chakra entres Kakashi's body. "Don't waste it," Wind says. "We could be fighting here for days."
"We'll all die if we have to fight that long," says Kakashi gravely, hoping it does not come to that.
"Rain will go for reinforcements as soon as he thinks we can hold our own for long enough," says Wind encouragingly. "Hopefully that is soon."
Kakashi sees Sei and Rain heading down the stairs to rescue the wounded Guard. The last fighting Guard is doing her best to defend the wounded one, but she is struggling.
Sei and Wind reach the Guards. Sei hoists his comrade onto his shoulders and carries her up the stairs. Rain faces down Black Zetsu, a kunai in each hand.
Black Zetsu charges at Rain, ignoring the last remaining Guard. Rain dodges Zetsu's attack easily. Before Zetsu has even completely passed Rain, Rain is already turning to attack, bringing both kunai down on Zetsu's back.
A hand shoots up out of the ground, grabbing Rain by the leg. Black Zetsu turns and punches Rain in the face, shattering his mask and sending him flying up the stairs. Kakashi does not see Rain's face before Rain crashes in the stairs. The force of impact puts a huge dent in the stairs, and Rain stays where he landed, lying face down in a pile of broken paving stones.
"NO!" screams Wind, an expression of horror on her face. A guttural scream escapes from her throat and she turns towards Black Zetsu. "HOW DARE YOU?!"
"You chose the wrong side," says Black Zetsu calmly. "We will win."
Kakashi takes a step back, away from Wind as powerful chakra begins to bubble out of her. It swirls around her body, angry red in colour. Her cloak flaps about her legs and her hood blows off, revealing dark hair. The bubbly red chakra forms a tail.
Bijuu chakra.
Wind charges through the lines of white zetsu to attack Black Zetsu head on. With a scream, Wind throws a chakra-enhanced punch at Black Zetsu.
Zetsu stops her punch by grabbing her fist and sucking away the bijuu chakra cloak. With his other hand, Black Zetsu grabs Wind's mask and tears it off saying, "Why don't you show everyone your face, girl?" Then he throws her up the stairs where she lands beside Rain, her back to Kakashi. The other Guard runs up the stairs to help Wind and Rain, but Zetsu cuts her down, killing her instantly.
Wind struggles to her knees and rolls Rain onto his back so that she can heal his injuries. She is shaking as her hands begin to glow with healing chakra. Rain's injuries begin to heal as Wind pours as much chakra as she can into healing him.
Kakashi can see their faces now. There is no way it is possible, and yet…
"Rin? Obito?"