Hashirama does not have the skin or eyes typical of an edo tensei, which means that we still have a chance at winning. As I'm contemplating what I can actually do against Zetsu I hear the village alarm blare loudly, then abruptly stop before it starts again and stops in this manner twice more. That's the signal for a pincer attack.
Looking behind me reveals a wave of earth, thankfully much smaller than Zetsu's sand mountain, incoming towards the village. The edo tensei of Konan, Jiraya, Yagura and twenty edo tensei that I don't recognize are riding atop the wave. We have no chances of winning a battle of attrition.
I rush towards Zetsu, making sure to keep him in my field of vision. Once he is in range of Amaterasu I immediately blast him with it. The black flames seem to be burning him, but he is regenerating faster than they can damage him. I try to use kagutsuchi to make the black flames pierce him, but that does not appear to do anything to him.
Zetsu slows down, allowing the sand behind him to envelop and hide him. I make twenty one shadow clones and then dash towards him as fast as I can. The shadow clones start throwing different combination jutsu into the sand mountain with the hope of seeing what's most effective. I activate my Susanoo right before reaching the sand and diving into said sand mountain.
I move the susanoo around, trying and failing to touch him. The sand begins to create increasingly more pressure against the susanoo, beginning to crack it more and more. I don't have much more time left. By the time that my susanoo is covered in cracks I still haven't managed to find him, so I blow myself up.
I am seeing edo tensei Sakura, who appears to be surprised. My vision is somewhat different compared to usual, as if I'm seeing chakra in more detail. Looking around reveals I am atop the Hokage tower. Nagato, Tsunade, Hinata and Onoki are fighting the edo tensei. On the other side of the village the sand dune is starting to be alarmingly close. I look at Sakura and she nods. "We'll take care of the edo tensei, go and buy as much time as possible against Zetsu, we'll join you once we're done here. By the way, you've finally awoken the rinnegan."
That's honestly the best news that I've heard thus far. I nod and rush towards Zetsu. Once I'm on the wall I spam the shadow clone jutsu, making sure that there's more than enough shadow clones to surround the whole village in black flame barriers. I don't stop until Zetsu has almost reached the village, at which point I jump towards him, the clones immediately forming the barrier as soon as I jump, and blast the dunes with a max powered shinra tensei.
Zetsu wasn't in the center of the mountain. I find him on the bottom, to the left. He is not covered in black flames anymore. Once he becomes visible he hits me with his own shinra tensei, violently slamming me into the barrier and disintegrating my body. As soon as I'm reformed enough to form a susanoo I do so, which is a good thing since I'm immediately covered by sand after I do so.
Being an edo tensei allows me to pump much more chakra than usual into the susanoo, allowing it to remain standing against the pressure. I use amaterasu and kagutsuchi to burn as much of the sand as possible, which does not seem to be having any effect whatsoever.
After a minute of blindly burning away at the sand it is thrown away by a barrage of rasenshuriken. Naruto lands next to me, cloaked and in sage mode. "Any plan?"
I dart my eyes and blast all the sand in my sight with Amaterasu. "No plan at all. Just kill the fucker."
"Pff, just watch me then."
Naruto then rushes at Zetsu almost faster than I can see, beginning the fight with a mean uppercut. I rush towards the two of them, blast Zetsu with amaterasu and form a Kagutsuchi barrier around the three of us, preventing any sand from being brought in. As I was rushing towards them I analyze Zetsu's fighting style. It's pretty weird, somehow both inexperienced but heavily practiced at the same time. As if he intellectually knows the moves, but hasn't actually put them into practice. Halfway towards them the dome of black flames has already been covered in sand.
I land behind Zetsu as he misses kicking Naruto in the head, throwing a roundhouse kick at Zetsu's head in the process. Zetsu dodges too late and is forced to take the kick. Naruto takes advantage and lands a savage roundhouse kick to Zetsu's knee, breaking it. By the time that I form a wind-charged chakra scalpel said knee is already fully regenerated. I take a swipe at Zetsu's arm, cutting it off. Zetsu tries to kick me away but instead gets kicked in the head by Naruto.
I take a swipe at his legs but get sucker punched by the same arm that I had just cut off, sending me flying away. Zetsu jumps and begins rushing through handsigns. Naruto begins forming a rasenshuriken. Zetsu finishes weaving his handsigns, exploding all of his skin into gore and getting rid of the black flames that were on him.
Before I can use amaterasu to set him on fire again he surrounds himself with wood, forming a wood cocoon. Amaterasu lands on it and I use Kagutsuchi to make sure it sticks this time. Naruto's rasenshuriken lands afterwards and blows the wood cocoon to smithereens. Zetsu isn't in the cocoon.
Zetsu rises from the ground behind Naruto, trying to sneak attack him. Naruto's sage mode instantly tips him off, allowing him to throw a spinning back kick into Zetsu's face, sending him flying into the black flame barrier. I use kagutsuchi to envelop Zetsu in black flames as soon as he touches the barrier.
He tries to use the same jutsu to blow his skin off again but ends up getting violently kicked into the barrier by Naruto again. I land to his right and slash his arm off. Naruto breaks one of his knees again and I try to cut his head off. Zetsu ducks and kicks me away from him. Naruto uppercuts Zetsu and dodges a punch from the same arm that I cut off. His regeneration is starting to slow down a little.
While I'm flying away Zetsu glances at me, looking into my eyes as he does so. I don't hesitate to try and use genjutsu to paralyze him, regardless of whether it would work or not. He breaks the genjutsu almost immediately, but not instantly. That allows Naruto to kick his left knee and break it again. Zetsu then pushes Naruto away with a shinra tensei, violently smashing him into the other side of the barrier. I finally land and jump right at Zetsu, using amaterasu as I do so. Zetsu uses the preta path to absorb the amaterasu flames.
I land behind him and use Shinra tensei to push him into Naruto, who has recovered and is currently running towards the two of us at full speed. Zetsu fails to dodge Naruto's punch, which visibly breaks his spine. I use amaterasu and it is immediately absorbed with the preta path again.
I take a deep breath. As an edo tensei my taijutsu is severely hampered by the lack of the eight gates and the heavenly seal. If I bring myself back to life so that I can use them then I wouldn't be able to sustain the barrier and we'd end up getting crushed to death. Using the rinnegan to remove Zetsu's soul is more likely to pull out Hashirama's soul instead, which is probably going to make things easier for Zetsu.
I form wind-release chakra scalpels on both of my hands and rush towards Zetsu. Our only practical win condition is to either make him run out of chakra, preventing him from regenerating further, or for him to make a mistake and allow us to land a killing blow on him. Naruto breaks Zetsu's knee again, allowing me to cut the other leg off. Zetsu raises his arms and begins to use chibaku tensei. Naruto breaking the same knee again fails to stop him. Zetsu is now in a very compromising position. His hands are risen above, preventing him from using them to block. One of his legs is momentarily useless because Naruto has just broken it and the other is only halfway regenerated. I bisect Zetsu in half but still fail to kill him. He leaned his head to the right, allowing his brain to remain untouched.
Naruto punches Hashirama's falling head with both of his arms. One arm coming from the left and the other coming from the right. Zetsu detaches from the head before it is burst open by Naruto. I burn Zetsu with amaterasu, he has no escape this time.
Naruto throws a rasenshuriken at him for good measure, turning him into gore. The sand has stopped applying pressure into the barrier, so I take the barrier down and use wind release to blow the sand away. What greets me is a desert. There is sand as far as I can see, the forest surrounding us has been buried in sand. Konoha is fully buried in sand as well.