Mei's eyes eagerly stalked her prey as she sneaked through the mist towards the Kumo troops. She asked Rei to let her join the ninjas who will be attacking the Kumo troops and only with great reluctance, she was let go at the behest of Konan. Mei was happy that Rei cared about her but she also wanted to show him she was not someone he had to protect all the time. This, in her opinion, was the perfect opportunity.

The tension was high in the air as the Kiri-nin tried to get as close as possible without being heard or seen. The surroundings were covered in thick mist and this was their forte, after all. None of them wanted to fail and disgrace themselves. ​​

Mei deemed herself being close enough as she heard nervous banter coming from a few meters in front of her. It was obvious they were Kumo ninja because no Kiri-nin would talk out loud in the mist, much less when they were about to attack the enemy. She crouched down and whipped ten shurikens from her pouch, half-turning her head to the side to check where her teammates were. She could only use her hearing to do that but Rei made her often practice in a thick boiling mist made of her Boil Release so she could proudly proclaim she was even better than some jonin at navigating through a mist just with her ears.

'Five from my squad are approximately ten meters to the left of me...' Mei thought as she registered their covert footsteps. It was almost completely silent and she had to applaud the sneaking skill of her squad-mates. She would be unable to hear it if Rei didn't teach her how to enhance her hearing with chakra. She tilted her head to the other side and nodded to herself. 'The remaining four are to the right... eight, nine, and eleven meters away.'

The slightly chilling world of white all around her was something Mei loved. It was this world of white where she made the best memories with Rei. Her lips bloomed into a smile as she remembered one training session with Rei that ended with her sprawled on the ground, entangled with Rei. She would always cherish his embarrassed expression...

" 'If there is a thick mist... why not make it melting?' huh?" She fondly muttered under her nose as she remembered what Rei told her during that particular training. "Well... fair enough." Mei silently molded her chakra, praising Rei for literally forcing her to learn sealless chakra molding. She only dared to do this because Rei gave her a special seal that managed to hide her chakra usage from sensors unless she used a certain amount of it at once. A very nifty seal for the current situation... It took about a minute until Mei was ready, which made her frown as it took her way too long... well, she was not yet ready to use the sealless molding during combat, especially not since she had to limit her chakra output.

"Boil Release: Melting Clone."

Two copies of herself suddenly solidified from the mist around, also drawing ten shurikens. The three of them eagerly awaited the signal to start. After all, as Konan-nee told her, she had to prove to Rei she was worthy of him!

It took almost ten whole minutes until Mei heard the loud explosion signalizing the start of the attack and she could instantly feel the shockwaves from it spread through the clearing, ripping apart the mist. If she didn't know what to expect and wasn't properly anchored to the ground with her chakra, she would surely have a hard time keeping herself in one spot.

Each Kiri ninja threw their prepared shurikens towards the Kumo troops the second they heard the explosion, creating a shower of sharp steel. . Most of the shurikens were redirected due to the strong winds the explosion created but those that were properly aimed were enhanced by the shockwaves and rained on Kumo ninjas in a flurry of death.

Mei delightedly noted that all thirty of her shurikens found purchase and thanks to the additional push by the shockwaves, the Kumo army was now forty-three men short. She knew the initial hail of steel was only a good distraction and time-efficient action. It didn't really have much of a meaning in the grand scheme of things as not that many Kumo ninjas were caught off guard and mostly mercenaries died. Mei instantly followed the next part of the plan. The mist was almost dispersed but the unexpected strong winds created enough chaos and distraction to the enemy that the Kiri ninjas were still unnoticed. The bodies of Mei's targets from the shurikens didn't even manage to fall onto the ground as she was already channeling her chakra.

"Henge!" She exclaimed quietly and together with her clones, she jumped towards the distraught Kumo ninjas as her attire changed into standard Kumo ninja uniform while according to Rei's plan, she also threw a smoke bomb right in the middle of enemy troops to create another cover for herself and her allies. What Rei didn't tell Mei nor any other Kiri ninja, the seals that previously masked chakra usage had also a function of enhancing their Henge to seem more natural which made them harder to see through it.

...

The Kumo troops were utterly unprepared for the powerful shockwave from the explosion. Worse yet, none of them anticipated a hail of steel to rain from all around them as every Kiri-nin threw out shurikens the second the explosion resounded through the clearing. But it was only after that the real hell began. The surrounding white mist was blown away by the strong winds but the visibility didn't return for long as smoke bombs started to explode everywhere around and the slaughter began. People wearing Kumo uniforms started hacking and slashing mercenaries... The real shitstorm however started when the mercenaries began to return the attack, and the clash between the people clad in the Kumo uniform and the mercenaries commenced.

...

Mei slit the throat of an old-ish burly man with her kunai and saw one of her clones, henged to look like common mercenaries, fighting with a sword-wielding Kumo-nin while the other was throwing kunai and shurikens around while quickly zig-zagging through the labyrinth of people fighting each other. The poor guy who fought with one of her clones was swiftly dispatched when his sword impacted the forearm of the clone and his expression turned to delight as he expected the arm of his opponent to be chopped into two, only for the arm to flicker and change into a boiling mist that enveloped the man's head, melting it. It was painful but a quick death… before the clone's arm again reformed as it turned to look for a new target.

Mei didn't waste her time and quickly found a man wearing a Kumo uniform who didn't have the seal-tag from Rei, meaning he was not one of the disguised Kiri ninjas. The man was distraught as he didn't know who to attack in this utter chaos where allies killed allies in hopes to kill the real enemies. Moreover, the entire battlefield was covered in smoke, clouding the visibility, and only blood-chilling and blood-curdling screams could be heard all around alongside the deafening sounds of steel hitting steel! He had no idea what to do!

Mei smiled to herself and shouted at the man while approaching. "Are you alright!?" She asked, getting his attention. The man briefly tensed until he saw her Kumo attire. "Don't just stand around! Be careful or you will die!" She admonished the man whose face momentarily twisted to embarrassment before he gave her a curt determined nod of gratitude and raised his guard. Mei was now very close to the man and smiled. "Don't worry, I have your back." She said, making him smile.

The second he acknowledged he heard her and turned around, the man instantly regretted it as his heart was pierced from behind by Mei's kunai. "I warned you I have your back, didn't I?" Her amused voice was the last thing the man ever heard as his eyes dimmed and his lifeless body fell to the ground. Mei snorted and jumped away from the man, becoming just another shadow in the surrounding smoke.

She jumped out and into a battle, killing distracted people who didn't have seal-tags from Rei. It affected others who wore the same seal with a minor unbreakable genjutsu, making them see a bit of translucent blue hue around them, marking them as allies. Mei also supported any ally who was in pinch and mostly acted like a proper ninja. Never staying too long to battle one guy and seldom participating in one versus one unless she had an overwhelming advantage or her enemy was gravely injured. The Kiri ninjas were assassins and right now, the smoke-filled clearing was the best possible battlezone for them. Mei especially liked when she saw two people clashing and none of them having the seal as it was a clear sign that their tactics were working perfectly and Kumo troops were killing each other with fervor. It was almost hilarious and exhilarating to see how well Rei's plan went.

This was the first major battle for Mei where hundreds of ninjas clashed and only now she understood the teachings of Rei. He often told her "If you don't have overwhelming strength, then stealth and mind-games are your best friend." Right now, she had a clear example of that. Kumo ninja couldn't use large-scale jutsu in fear of hitting their own and that left only close-combat available to them. They also had to be wary of anyone who approached them, even the people they knew while the Kiri-nin just picked the 'unmarked' enemies one by one from the smoke with silent killing technique while occasionally changing their disguise to look like a guy who they recently killed. The overwhelming numerical advantage of Kumo was completely nullified and turned against them as chaos ruled the battle and the massacre continued.

'Isn't this a bit too easy?' Many Kiri-nin thought while dispatching their targets and couldn't help but admire the simplicity of Rei's plan while also being exasperated. Who in their right mind would drag tons of natural mist sealed in storage scroll with them!?

----

Author Note:

Okay! This was my first writing a major battle, guys, and as you saw, I tried to depict how tactics and the control of the environment made it easy for Kiri-nin...

Do give me feedback as I dunno how well this was written and feel as if it could be better :D. Alas, writing about clashes between armies is something I will have to improve, I guess.