While the frontline ninjas fought valiantly, the medical ninjas in River City were also running back and forth in a frenzy. In this crucial battlefield, the medical camp had to transfer some personnel; the people Tsunade had brought earlier couldn't handle so many casualties.
Tsunade directed the medical work while listening to intelligence reports on the frontline situation. Before setting out today, she already knew that the decisive moment for victory would be today. When to dispatch the surprise attack unit depended entirely on her judgment.
"Lady Tsunade, Lord Kagami has encountered the Kazekage, and they are currently fighting." The intelligence officer informed Tsunade of the latest information, adding to the previous report that Hatake Sakumo and Chiyo were engaged in battle. Both sides' high-level ninjas had fully entered the battlefield.
"They must be giving it their all." Tsunade wiped the sweat from her forehead, caught her breath, and pondered silently. She quickly walked to the door and gazed at the battlefield.
The Sand and Leaf ninjas were like the black and white colors of a Tai Chi diagram, distinct yet tightly intertwined. At this moment, the Sand ninjas' color was slowly encroaching on the other side. Overall, the Leaf ninjas were slightly at a disadvantage, but both sides' combat power was very close, so the Sand ninjas couldn't resolve it quickly.
To support the battlefield, Tsunade had already summoned a large slug earlier, using Slug: Great Division to send numerous small slugs to every position, providing quick healing for lightly injured ninjas. The immense chakra of a Senju descendant was transmitted to every injured person via the slugs.
On the battlefield, there was no time to slowly treat wounds. Except for those requiring surgery, all others were quickly treated this way. This was something only Tsunade's medical expertise could achieve.
Because Tsunade bore a huge burden, routine surgeries were handled by other medical ninjas. However, even with Tsunade's support, there were still many severely injured, and the medical ninjas in the rear were extremely busy, sometimes even needing Tsunade to personally assist.
Seeing this, Tsunade knew it was almost time. She quickly said to the small slug assisting in intelligence gathering, "Please inform them."
Previously, the slug had already learned the full scope of the plan from Tsunade, so it immediately understood who Tsunade was referring to. It nodded gently.
At the same time, in a certain valley in the Land of Rivers, the surprise attack unit was waiting. For the sake of secrecy, they had no other way to obtain information from the outside world; only the slug remaining with them could tell them about the external situation.
The valley was very quiet, giving a sense of being cut off from the world. Initially, the surprise attack unit members would chat, but as time passed, they gradually grew anxious because the war was still ongoing, and people they knew might have died at any unknown moment.
Three days prior, they learned from the slug that a large-scale battle had begun. They guessed their time to appear was approaching, but three days passed without them being called, making them restless with impatience.
At this moment, the small slug, which had been quietly beside them, suddenly spoke: "Everyone, please prepare. Lady Tsunade will be here soon to take you to the battlefield."
These words were like a heavenly melody. The surprise attack unit members immediately stood up excitedly. They had long been impatient about doing nothing while stuck there. Someone shouted, "Finally! I'm already itching to go cause trouble for the Sand ninjas. This time, I'm taking out two squads by myself!"
"What's two squads? I'll take three!"
"Tch, only three? I'll take five by myself!"
Whether they were boasting or not, the only message they wanted to convey was—they wanted to fight the Sand ninjas. Each person spoke while picking up their weapons placed nearby. In less than a minute, everyone was ready, just waiting for someone to appear.
Beneath the small slug, the summoning jutsu formula appeared. It used the Reverse Summoning Jutsu to summon Tsunade from distant River City.
A puff of smoke rose, and Tsunade appeared before everyone. Tsunade barely had time to catch her breath before telling them, "It's your turn to appear. Follow me."
With that, Tsunade, without waiting for their reply, once again used the Summoning Jutsu. This time, she summoned a giant slug, large enough to envelop everyone.
The surprise attack unit members knew they would be transported by the slug. They immediately entered the slug's body. The slug moved its soft body to wrap them inside, and Tsunade watched them enter one by one.
Once everyone was inside, Tsunade jumped to the top of the slug's head, instructing it to transmit its will to the small slug in River City, telling it to use the Reverse Summoning Jutsu.
After a slight sensation of spatial displacement, the giant slug appeared on the battlefield, causing a certain shock to both sides. Nearby people looked up at Tsunade on the slug's head. Tsunade's breathing had become somewhat heavy. She formed hand signs and shouted, "Slug: Great Division!"
The giant slug's form seemed to explode, and countless small slugs flew in all directions. Each slug was the size of a normal person, carrying one individual, rapidly deploying them onto the battlefield.
After performing Slug: Great Division, the giant slug still maintained a certain size, though it had shrunk by more than half. Tsunade couldn't help but kneel, as even for a descendant of the Senju clan, the pressure of repeatedly summoning slugs while maintaining medical support for the entire battlefield was still quite immense.
"I hope the plan goes smoothly." Tsunade threw two military rations into her mouth to quickly replenish her stamina, reserving chakra reserve pills for more critical situations. Then, she retreated using the slug's body as cover.
The Sand ninjas had seen the Slug: Great Division before, so when they saw it again, they didn't immediately pay close attention. As a result, when the slugs landed near them and Leaf ninjas burst out, they were caught completely off guard.
By now, everyone had exerted a great deal of power, overusing chakra and losing significant stamina. Facing energetic Leaf ninjas, combined with the advantage of a surprise attack, many were taken out without even a chance to react.
After the initial shock, the Sand ninjas finally reacted. Even so, with severely depleted stamina, it was extremely difficult to withstand the attacks of these fresh forces. This situation occurred in various positions, catching the Sand ninjas off guard, while the Leaf ninjas, after a brief moment of astonishment, understood that reinforcements had arrived and once again burst forth with new strength.
"What's going on? Where did these Leaf ninjas come from?" one elite Sand ninja said with doubt and surprise. While fighting, they hadn't forgotten to gather intelligence; there were clearly no Leaf ninja units approaching from around. Even if it was slug transfer, where were these people from?
At this moment, a slug crashed heavily near him. He immediately turned around, gripping his weapon nervously, but the person who emerged from it made his pupils constrict slightly, saying in shock, "You're Uchiha Ken, how is this possible?!"
He remembered very clearly that Uchiha Ken had been eliminated as a member of Konoha's rogue ninja group, but how could he suddenly appear here perfectly fine?
"…It's you." Uchiha Ken briefly recalled, then remembered encountering this person in a past battle. His strength was decent, but there was still a significant gap between them.
After the opponent regained his senses, he realized he should immediately counterattack, regardless of why the other party appeared here. However, it was already too late, because in that brief moment, the Sharingan's genjutsu had already invaded his consciousness, stiffening his body.
Already exhausted from the prolonged battle, and with Uchiha Ken's pupil power enhanced by his Mangekyo Sharingan, the Sand ninja had no means of resistance and was finished off by Uchiha Ken with a single genjutsu followed by a thrown kunai.
After eliminating the familiar Sand ninja, Uchiha Ken dashed towards other areas, chakra condensing in his feet, instantly erupting with astonishing speed. His Sharingan rapidly captured the situation from all directions, and in a mere blink of an eye, many Sand ninja met their demise at his hands.
The arrival of the surprise attack unit immediately brought about a significant change to the previously stalemated battlefield. The Sand ninja had already brought their forces to nearly 100% capacity, and faced with the sudden surprise attack, they were unable to mobilize additional strength to fill the gaps, watching as the balance was broken.
Previously, the Sand ninja had been subtly suppressing their enemies, but now the situation had reversed. The Sand ninja were on the defensive, and their positions were constantly being lost and overrun by the newly arrived Leaf ninja.
Ebizo, Chiyo, and others who were in combat also noticed this, but they were unable to attend to it because their opponents had changed their fighting style, their attacks becoming more ferocious, leaving them no way to disengage.
"Is this your plan?" Ebizo lost his previous composure. "Since when have you been hiding this surprise force?"
"Guess." Uchiha Mirror smiled, moving his body while using Fire Release to disrupt Ebizo's movements. Whenever Ebizo showed any intention of disengaging, he immediately intensified his attacks.
Ebizo had no choice but to confront him head-on. Exposing his back would mean revealing his fatal weakness to his opponent, and a master like Uchiha Mirror would not miss such an opportunity.
What he had initially thought would be a prolonged battle advantageous to his side was now slowly becoming a noose choking him. Ebizo found it difficult to accept this turn of events. He could only quickly defeat Uchiha Mirror to help others, and Chiyo thought the same.
However, the next scene forced them to change their minds once again.
The advantage on the battlefield was slowly shifting towards the Leaf ninja. As long as Uchiha Mirror, Hatake Sakumo, and others could hold off their opponents, victory should belong to the Leaf ninja. However, in Uchiha Ken's opinion, this speed was still a bit slow, and there was still the possibility of variables.
—The battle must end quickly, both for the victory of the war and to prove himself.
Uchiha Ken's mind raced. After dealing with his current opponent, he soared to the top of a hill, overlooking the battlefield below from a high vantage point. He shouted to a nearby Hyuga ninja, "Hey! Come help me."
"What?" The Hyuga ninja was momentarily stunned by the words. The current situation was good, and the other party was his comrade. Since he had time to help, he came to Uchiha Ken's side with some surprise and asked, "Is there anything you need help with?"
"Help me check the surrounding situation. The jutsu I'm about to use isn't so easy to control." Uchiha Ken's eyes were blood red, the tomoe within them spinning rapidly, then connecting to form a new pattern.
"Th-this is…" The Hyuga ninja was shocked. He had never seen a Sharingan like this before. What was going on?
Uchiha Ken had no time to answer him. He tightly closed his right eye, his pupil power rapidly condensing within it. Perhaps due to the immense power, a painful sensation made him frown, followed by a moist liquid flowing from the corner of his eye, down his cheek.
"Hey, your eye!" The nearby Hyuga ninja saw clearly that Uchiha Ken's right eye was seeping blood, causing him to exclaim in alarm.
"It's nothing, you don't need to worry!" Uchiha Ken took a deep breath, then suddenly opened his right eye. A large number of blood vessels surged in his eye, coupled with his crimson pupil, making him look exceptionally ferocious.
At the same time, wherever Uchiha Ken's gaze fell, a mass of pitch-black flames appeared out of thin air. Nearby Sand ninja were caught off guard and instantly covered by them. The black flames rapidly expanded, engulfing all the nearby Sand ninja, and screams echoed across the battlefield.
But because of the extreme speed, some Leaf ninja were also inadvertently caught. Although it was only a small amount, the Leaf ninja discovered with horror that these black flames could not be extinguished and were spreading rapidly.
Seeing this, the Hyuga ninja quickly said, "Hey! Even comrades are…"
"They'll be fine!" Uchiha Ken directly interrupted the Hyuga ninja's words. At this moment, Uchiha Ken's right eye was in unbearable pain, forcing him to close it. After catching his breath, his left Mangekyo Sharingan began to spin, its pupil power rapidly condensing. The black flames that had adhered to the Leaf ninja seemed to come alive, detaching from them and piercing through nearby Sand ninja who had not been touched by the black flames, like arrows.
This was the ability of Uchiha Ken's Mangekyo Sharingan. Due to the profound impression of his father's death in his childhood, the explosive flames were deeply etched into his heart, along with his subsequent doubts about the world, transforming into the indestructible flames capable of incinerating everything—the black flames that, in the mythology of the Sage of Six Paths, could burn for seven days and seven nights.
This was Uchiha Ken's right eye's genjutsu—Amaterasu. His left eye, on the other hand, possessed a genjutsu that could control the form and transformation of Amaterasu, further amplifying its range and power. This ability to freely control flames, in the mythology of the Sage of Six Paths, was the power of Kagutsuchi, known as the God of Fire. Therefore, this genjutsu was named Kagutsuchi.
If ordinary Amaterasu might allow people to timely abandon the affected parts due to its burning speed, under the control of Kagutsuchi, Amaterasu's cohesiveness was further enhanced. Just a slight touch would instantly engulf the entire person in black flames, naturally leaving no chance of survival. Some black flames even directly pierced through the Sand ninja's hearts with their high temperature, swiftly and decisively taking their lives.
The Amaterasu of the right eye and the Kagutsuchi of the left eye were the powers of Uchiha Ken's Mangekyo Sharingan. The Mangekyo Sharingan, unseen since Uchiha Madara, once again displayed its prowess today.
Under the control of Kagutsuchi's pupil power, the black flames that incinerated the Sand ninja reformed, taking on various shapes: ropes, arrows, or shuriken. Their forms were ever-changing, but their target was only one type of person: the ninja of the Sand Hidden Village.
Amaterasu could not be extinguished by ordinary means. After seeing that even Water Release had no effect, the Sand ninja could no longer suppress their inner fear, and their entire formation began to become chaotic. However, this only made it easier for the Amaterasu flames to slaughter them.
The nearby Hyuga ninja watched Uchiha Ken, whose eyes had begun to stream blood, and took a deep breath. The latter seemed oblivious to the abnormality on his body. He stared intently at the battlefield, occasionally asking the Hyuga ninja about the enemy's positions.
Looking at the blood-soaked face, the Hyuga ninja suppressed his inner fear and reported the enemy's positions to Uchiha Ken. Uchiha Ken then controlled the black flames to pursue the enemies based on the other party's descriptions. Under the effect of Kagutsuchi, the black flames moved exceptionally fast, and the Sand ninja had almost no chance of escaping.
When the Hyuga ninja's reports could no longer allow Uchiha Ken to accurately grasp the positions, Uchiha Ken asked the Hyuga ninja to call over a member of the Yamanaka clan for a mental connection, sharing the Hyuga ninja's vision. This allowed Uchiha Ken to better control the black flames to pursue the Sand ninja.
Listening to the continuous screams on the battlefield, the Hyuga ninja couldn't help but recall the rumors he had heard about the Sharingan in the past, thinking, "These unheard-of Sharingan truly are eyes like those of a demon."