For Asuna, the re-entry of Sunagakure into the battlefield was when she once again realized the cruelty of war. Just like the people in Konohagakure and on the Eastern Front, due to the smooth progress of the war, the ninjas on the Western Front, including her, had underestimated their opponents.
After all, Sunagakure had suffered a setback the first time it entered the Land of Rain, with its ninja forces retreating in disarray and over two hundred ninjas captured. Iwagakure also couldn't stand tall against the newly deployed Exploding Cannon, only able to defend using sturdy rock fortresses and seek methods for a counterattack.
After the heavy rain in the Land of Rain stopped, Sunagakure dispatched two ninja units, one entering the Land of Rain and the other entering the Land of Grass. At this time, Asuna and the others were already fighting in the Land of Grass. Although she heard the news of Sunagakure's entry, she didn't pay much attention to it at first. Sunagakure had performed poorly in the Land of Rain, and according to the established strategy, they couldn't possibly achieve anything in the Land of Grass.
However, Asuna knew that her thinking was completely wrong. The enemy wasn't foolish; how could they achieve the status of one of the Five Great Nations with such a country if they had no tricks up their sleeves? When they faced the enemy again, Sunagakure employed an exceptionally cruel method: poison gas.
As is well known, Sunagakure is a ninja village highly skilled in using poisons. Although the vast desert cannot grow crops, it is home to some extremely potent venomous insects and plants. This gives them unparalleled experience in the use of poisons compared to other countries, as other countries do not possess such potent toxins.
Previously, Sunagakure would only apply poison to their puppet mechanisms or ninja tools. But this time, Sunagakure installed a new mechanism in their puppets that could release poison in gaseous form, thus forming a poison gas puppet unit. No one expected this unit to be so dangerous.
Although they sensed something unusual about the enemy's puppet unit, their past advantage over Sunagakure made the ninja forces on the Western Front somewhat careless. As a result, they were unexpectedly caught off guard, and a large-scale release of poison gas directly poisoned the Konoha ninjas at the front. Without even a chance for rescue, they collapsed screaming, their skin covered in large red swellings. They screamed and scratched their bodies, not caring even as blood emerged, until they died covered in blood, a truly shocking sight.
Asuna never expected such a tragic scene, besides the bodies blown to pieces by the Exploding Cannon. Everyone was shocked by the power of this poison gas. Even if a ninja could hold their breath for a long time, that was in a static situation. Once they entered combat, they would inevitably need to breathe to give their body strength. In other words, Konoha ninjas could not possibly charge at the Sunagakure forces under these circumstances.
Especially since Sunagakure mainly used Wind Release, the poison gas would not affect their side at all, and they could even blow the poison gas over from a long distance. Even if they had to enter a gas-filled area, Sunagakure ninjas also had antidotes—when a poison is developed, a corresponding antidote must also be developed, otherwise, it cannot be put into practical use.
Of course, Konoha ninjas couldn't risk charging through the poison gas to seize antidotes; they could only choose to retreat. After the initial defeat, news also came from the Land of Rain that Sunagakure was also using poison gas there. However, due to the environment of the Land of Rain and the anti-gas masks commonly used by Amegakure ninjas, the Konoha ninjas remaining there performed better than those in the Land of Grass.
Hanzō realized what situation the Konoha Fourth Ninja Unit in the Land of Grass would encounter. He urgently mobilized the anti-gas masks from the village and sent them to the Land of Grass, which finally resolved Konohagakure's urgent crisis. However, because there were not many ninjas in Amegakure, it was naturally impossible to stockpile anti-gas masks on a large scale, and re-production was also very troublesome now due to insufficient manpower.
Therefore, the Konoha Fourth Ninja Unit re-strategized. Due to the production issues with explosive tags, the scale at which Exploding Cannons could be used also had to be carefully considered. Aside from those used to suppress Iwagakure, not many more could be used.
To prevent Sunagakure and Iwagakure from joining forces and using poison gas, Inuzuka Shigeru decided to deploy most of Konohagakure's remaining Exploding Cannons at the boundary between the two sides, using intense shelling to prevent their rendezvous. The remaining Exploding Cannons would then be used to obstruct Sunagakure.
However, these few Exploding Cannons were clearly not enough to gain an advantage in the war against Sunagakure. After the remaining anti-gas masks from Amegakure were delivered, Inuzuka Shigeru decided to have the elite units, equipped with anti-gas masks, launch a rapid assault, while the other Konoha ninjas provided support from the flanks, aided by the remaining Exploding Cannons.
Fortunately, the number of Sunagakure ninjas was far less than that of other countries. Inuzuka Shigeru's plan indeed halted Sunagakure's advance. If their numbers had been greater, the pressure on Konoha ninjas would have obviously been much higher, and they might have truly been overrun.
Even so, some Konoha ninjas or samurai still died tragically from poisoning. Hanzō also stated that he couldn't cure this poison. His body contained the potent venom of the salamander, so no poison could affect him, but that was because he had completely adapted to the salamander's gallbladder. Even if others tried to use the salamander's poison to fight poison with poison, they wouldn't survive.
Inuzuka Shigeru could only rely on the village's assistance. The village quickly sent an order, informing him that Tsunade of the Medical Department had already set off and would arrive in the Land of Grass soon. He hoped that the Fourth Ninja Unit could stabilize the front line as much as possible and reduce losses before Tsunade arrived. Once Tsunade developed an antidote, they would begin their counterattack.
Inuzuka Shigeru breathed a sigh of relief. He, of course, knew Tsunade's strength in the Medical Department. Konohagakure's medical capabilities were certainly superior to Sunagakure's. The only thing Sunagakure had going for it was the creator of this poison, the current Kazekage's older sister, Chiyo. He felt that even Chiyo couldn't surpass the village's most excellent medical ninja.
However, even in such a short time, Inuzuka Shigeru realized that the enemy was not so easily deterred. The defeat in the Land of Rain battle had clearly made them hold their breath, and from Sunagakure's internal policies, it was evident how far they had pushed their troops in this war, thereby greatly enhancing their combat capabilities.
Under these circumstances, Konohagakure mainly relied on its elite units. Even for the elite, Sunagakure's strength was not to be underestimated, and they naturally faced dangers. It was only thanks to top-tier experts like Sakumo Hatake that there were no massive losses.
But in the recent battle, even Sakumo Hatake encountered trouble. In the melee with the enemy, due to the strangeness of the puppets, he was caught off guard and pierced in the flank by a mechanism. The mechanism was naturally coated with potent poison, and once poisoned, even Sakumo Hatake would not be able to survive.
However, Sakumo Hatake's experience was still very rich. He knew how terrifying Sunagakure's puppeteers were. Few puppeteers had been able to defeat him in the past, but he also considered the situation of encountering danger and used a Lightning Release Shadow Clone to deceive the opponent, thus saving his life.
In a brief encounter, Sakumo Hatake noticed what the Sunagakure ninja who ambushed him looked like. He had seen that person before; it was Chiyo's son, Ryu, who had a grudge with Sakumo Hatake during the joint Chunin Exams. Over the years, the opponent's strength had clearly grown considerably. Although it was in a melee, being able to ambush Sakumo Hatake also proved his impressive strength.
—Truly, one cannot underestimate people from other countries.
Sakumo Hatake once again told himself this in his heart. In the current situation, even with his level of strength, he couldn't salvage the entire situation; at most, he could maintain a stalemate. Sunagakure's poison gas was truly a very troublesome thing, and he also had to be careful not to have his mask damaged by the enemy during combat.
And even Konoha ninjas couldn't be without any mistakes. In this battle, many Konoha ninjas were poisoned when their masks were shattered by the enemy, or had their bodies torn apart by Wind Release during an encirclement. Even on Sakumo Hatake's side, problems arose, let alone for others.
Asuna, for the first time in a long while, used Sage Mode chakra from her chakra reserve block, entering Sage Mode. With her rapidly increasing strength, she and Sakumo Hatake worked together to carve a bloody path for the others, forcing the enemy to retreat and gaining time for a ceasefire.
During this battle, while using Sage Mode chakra, Asuna tried to extend the duration of Sage Mode by taking the opportunity to draw a large amount of natural energy into her body. However, due to a miscalculation, she exceeded her physical limit—in the past, Asuna wouldn't have been in such a predicament, but during intense combat, maintaining a unified mind and body and energy balance was simply too difficult. If it were someone very familiar with it, they might be able to control a massive amount of natural energy and condense Sage Mode chakra in a short time, like Naruto Uzumaki in his later stages, but the current Asuna did not yet possess that level of control.
Fortunately, Asuna's own chakra was sufficiently vast. Even though she drew in more natural energy than she could control, it didn't lead to irreversible consequences. However, after the battle, the rejection reaction caused by the excess natural energy still made Asuna suffer greatly, and she collapsed as soon as she returned to the camp.
Once one is overwhelmed by natural energy, they will merge with the surrounding natural environment, most clearly manifested as the petrification seen in Mount Myōboku, a result of resonating with the earth. Asuna hadn't reached that severe stage yet, but she felt as if her cells were rapidly evaporating, her entire body developed a high fever, and she became extremely weak.
"Brother Sakumo, what will happen to Asuna?" Mizuki nervously paced around, shouting at Sakumo Hatake, whose face was also not looking good.
"I don't know. We can only wait for the results of the treatment." Sakumo Hatake shook his head somewhat dejectedly. He was just a warrior, only knowing simple medical methods, so he naturally couldn't offer any opinions in this situation.
As far as he knew, the Medical Department was also facing this situation for the first time. This severe reaction caused by excess natural energy seemed similar to certain diseases, but ultimately, there were still differences. If the exact cause couldn't be found, they could only see if other methods would be effective.
Hearing Sakumo Hatake's words, Mizuki instantly felt immense pain. The reason Asuna drew out her Sage Mode chakra at that time was to save her. Although Mizuki didn't know about Sage Mode, she could realize that Asuna was in this state because she saved her and others, which made her feel very guilty.
In these days, Mizuki's mood had been very suppressed. The painful screams of the poisoned people around her had a very negative psychological impact, and the atmosphere of the entire camp became gloomy. This suppressed mood finally reached its peak at this moment with Asuna's serious illness.
—Damn it, why is it this result? If I were stronger, Asuna might not have had to use that special chakra. Why haven't I awakened my Sharingan all this time? If I had the Sharingan, my strength would definitely improve to the next level.
—And those guys from Sunagakure! If they hadn't invaded the Land of Fire, why would she and Asuna have to fight so desperately? Those bastards!
Under the influence of inner pain and suppressed negative emotions, Mizuki suddenly felt her eyes become scorching hot, hotter and hotter, followed by intense pain. But she didn't cry out, only endured it silently. Due to the strong painful stimulus, tears flowed out uncontrollably.
Sakumo Hatake and Yamaka Risa, who were nearby, initially thought Mizuki was worried about Asuna. Although Sakumo Hatake felt the same, as a captain, he couldn't show weakness. Just as he was about to comfort her, he noticed Mizuki's dark eyes suddenly turn blood-red, with a black dot appearing in the center, and two 'tomoe' slowly emerging around the black dot.
Sakumo Hatake was greatly shocked. He, of course, knew that this was the Uchiha clan's kekkei genkai—the Sharingan. He never expected Mizuki to awaken it at this time.
At this moment, Mizuki hadn't noticed this. She was enduring the pain in her eyes. Just then, the curtain of the medical room was drawn back. She quickly stood up and walked over, asking the medical ninja who came out, "How is Asuna's condition?"
The person was startled by Mizuki's red eyes. Fortunately, he wasn't someone unfamiliar with the Uchiha clan's Sharingan. He immediately calmed down and told everyone the results.
Konohagakure's medical standards were indeed very high. Although they didn't have anything like Fukasaku Sage's staff that could draw out natural energy, they managed to suppress the powerful natural energy with other medicines. And since the amount of excess natural energy Asuna had drawn in wasn't too much, she ultimately survived.
"That's great…" Mizuki, hearing this, immediately relaxed. Due to the fatigue from the battle and the pain brought on by the awakening of the Sharingan, she also collapsed to the ground, unconscious.