Ichiro, Third, and Fourth finally learned to synchronize the technique, and it turned out exceptionally strong and dangerous. After discussing all the details of the plan, Kenshin double-checked all the formations on his sons' amulets and then went to bed, deciding to rest well before the upcoming battle.
In this operation, Kenshin was assigned the role of "commander", because he was the only one who could see the entire nearest area in the smallest detail, which was especially advantageous in pitch darkness. And although with increased physical characteristics, shinobi still saw in the dark anyway, Genin and Chunin could not boast outstanding night vision.
By nine o'clock in the evening, Kenshin was already awake and first checked what was happening outside. Seeing that the two strangers were sitting in their cave, Kenshin relaxed and once again briefed his sons.
By one in the morning, Kenshin made sure that the two strangers were asleep and, taking Ichiro, Third, Fourth, Fifth, and Sixth with him, headed to the needed cave; fortunately, it was only 400 meters from his hideout. He was not worried about the noise of steps, because the formation on all amulets was refined and muffled the sounds made by the user.
As soon as they approached the cave, everyone took their pre-agreed places, ready to act if necessary. Kenshin took a deep breath and once again checked the location of the strangers, mentally ordered "Begin!"
Three of his sons instantly synchronized telepathically and with millisecond precision began forming seals, and then all three shouted:
"Katon: Goukakyuu no Jutsu!" Releasing a five-meter fireball that immediately flew into the depths of the cave. They put 70% of all their chakra into this technique and worked at the limit of their capabilities.
Without wasting time, Kenshin immediately deployed a crudely made formation from sewn hare skins with five amulets sewn in certain places that were the basis of the formation. As soon as the fireball rushed forward, Kenshin threw the formation on the ground right in the center of the cave entrance and instantly activated it, barely managing to finish.
Small bursts of fire escaped from the cave, and if not for the formation, they would easily burn Kenshin's face. The formation on the ground was a modified version of the formation applied to each family member's amulet, with several changes. It worked only in one direction and let oxygen through so that the fire could burn without problems.
As soon as the fireball formed, Izao and Toru instantly opened their eyes. Their combat instinct kicked in. Seeing a huge fireball at the end of the cave, they understood there was nowhere to run, so each tried to save himself as best he could.
"Suiton: Suijinheki!" Toru shouted, and a thick water wall appeared in front of him just as the fireball was a few meters away.
The water wall did not help at all and was evaporated in a second, and the fire swallowed Toru along with it, leaving not even bones.
Izao was much luckier because he was sleeping behind a small stone ledge right next to the wall and thus received slight natural protection. He immediately formed several seals and shouted:
"Doton: Shoheki!" And a small rocky slab about 40 centimeters thick rose in front of him. He deliberately poured more chakra so the structure would be stronger.
As soon as the stone wall formed in front of him, Izao began forming new seals. But due to the complexity of the technique being performed, it was quite slow. And although the initial tangential fireball strike was contained, largely thanks to the natural ledge, Izao had little time left.
A few seconds later, the fireball crashed into the end of the cave and spread flame along all walls. Izao, seeing the expanding and rushing toward him from the sides tongues of flame, accelerated to the limit, and in the last second, one of the flame tongues still "licked" him.
Izao with a burned face and burnt hair instantly threw himself back and fell into the wall, holding his breath, freely traveling in the mountain rock in search of an exit.
*****
As soon as the technique was formed and the barrier activated, Kenshin instantly climbed the nearest tree with Fifth's help and began observing what was happening inside the cave.
When he saw one of the strangers burn in the fire, he was noticeably pleased and reported via telepathic link "One dead, but do not relax, stay alert!" and began watching the second.
As soon as Izao disappeared into the wall, Kenshin instantly reported "Doton user went into the wall, everyone scatter and hide!", and all his sons immediately took covert positions in different places, waiting for the enemy.
Half a minute later, Izao emerged from the wall and took a deep breath. He intended to get away from here as quickly as possible and was in no hurry to engage in a dangerous fight with an unknown opponent. His life was still dear to him, so he attempted to escape.
But Kenshin was not going to let him go. If one of the enemies could escape, a constant danger of attack and revenge could hang over the Nakayama family, so seeing Izao emerging from the wall on the "radar", he instantly commanded:
"Eight o'clock, fifty meters, Ichiro, act!" Hearing his father, Ichiro instantly looked in the right direction and activating Sharingan saw the enemy. He immediately threw two shuriken at him and rushed in pursuit.
Izao instantly saw the shuriken flying at him and saw nothing dangerous in them. But as soon as the shuriken were five meters from him, they suddenly disappeared, and one shuriken appeared right near his heart, and the other near the femoral artery.
He was stunned and barely managed to parry the first shuriken and only slightly turn his leg, avoiding damage to the femoral artery. The second shuriken embedded halfway, and Izao winced painfully but immediately pulled it out of the wound and realized that now he could not escape.
"Doton: Iwadeppo no Jutsu!" Izao shouted, and on exhale four small stones flew out of his mouth, rushing like bullets toward the approaching Ichiro.
Thanks to Sharingan, Ichiro perfectly saw the trajectory of the stones' flight, but his body was not that fast, and he managed to dodge only three; the fourth hit him in the right shoulder but was stopped by an invisible barrier.