Dan lay in the middle of the large room he had specially prepared for this operation—a spacious, empty room in his private house, away from noise, with fur spread on the floor and dim lighting from a small window. He had strictly ordered his women that no one should disturb him during this period no matter what, as he would be in isolated and very important training, warning them that any disturbance could be dangerous. The girls understood it was a type of special training and obeyed him without question.
Dan slowly closed his eyes, took a deep breath, and began clearing his mind of any distracting thoughts. He focused only on his body, his chakra, and the map of the seal he was about to apply. After several minutes of deep meditation, he was perfectly ready: his mind clear, his focus at its peak, and his body relaxed but prepared.
Then, using his superhuman chakra control, he began creating very precise new seal marks inside his body—small, complex marks requiring micro-level control. He linked these new seals to the existing ones on his bones, which were part of the original Vitality Seal applied years ago. Very slowly and with incredible precision, he began extending the new seals from the bones toward the surrounding muscles, muscle by muscle, in a process requiring incredible focus, patience, and chakra control. He felt every step, every small seal forming, and every thread of chakra connecting to the previous seals.
As soon as the seals began expanding to include his muscles, a massive painful sensation spread throughout his entire body, as if he were being grilled on fire from the inside. Every muscle in his body was burning, aching, and cramping. The pain was almost unbearable, enough to make any ordinary person scream and stop immediately. But Dan ignored it completely; even his facial features did not change, remaining calm and cold as usual. His pain tolerance was very high, especially after all the harsh training he underwent over the years: training under immense pressure in deep water and strenuous physical exercises. All that built in him a massive capacity to endure pain, so he continued without stopping, focusing only on the process and completing the seal perfectly.
Around him, a massive and pressing wave of his aura and chakra began to spread—a very strong wave filling the room and leaking through walls and doors. Dense spiritual pressure and energy made the air itself seem heavy. Even the girls in their distant house felt it clearly. They all stopped what they were doing and looked toward Dan's house, the source of the strong aura. They felt a mixture of curiosity, anxiety, and awe; this was the first time they felt Dan's true power so clearly and intensely. It was terrifying and amazing at the same time, but they did not interfere as he ordered; they just stood looking anxiously toward his house, praying in their hearts that he would be fine.
Dan continued for long hours, motionless, eyes closed, just continuing to engrave longevity into his body step by step, muscle after muscle, seal after seal, with full focus and perfect control. The process drained much of his chakra; had his reservoir not been massive now thanks to years of training, the original seal, and awakening his Kekkei Genkai, he wouldn't have been able to continue without stopping.
Then, after about 9 hours, the wave of aura and chakra around him disappeared with sudden speed, as if it evaporated into the air. Even his presence itself became very faint, almost imperceptible. The sound of his breathing vanished completely; even if he wanted to pretend to be dead, no ordinary person could tell the difference. This was exactly what Dan wanted: part of the improved seal is sealing chakra leakage, blocking all natural outlets from which chakra leaks, making him nearly undetectable—a ghost that cannot be tracked unless he reveals himself.
Dan slowly opened his eyes, with clear features of happiness on his face and a rare slight smile on his lips. He had finally succeeded in applying the improved seal perfectly, without any problems from start to finish. He had taken a big step forward toward his goal, toward immortality. Currently, he felt clearly how his muscles began to be nourished and improved, just as happened with his bones and marrow before. He felt the flow of chakra in every muscle, nourishing it, strengthening it, making it denser and more powerful. It was an amazing sensation, as if his whole body was being born again, renewing itself, and becoming much stronger than it was. At the same time, this process reflected on his other organs better and more effectively than the first version of the seal.
Dan stood up slowly, moved a bit, tested his new muscles, and felt a big difference. He felt his strength improving automatically without stopping; everything was improving—response speed and endurance. He was confident that his physical strength would continue increasing significantly over time. Also, he could now control his presence, making it very difficult for any ninja or fighter with sensory skills to detect him—completely hidden. It was a massive improvement in all aspects. Most importantly, he feels his lifespan beginning to extend again with the improved efficiency of his body organs. Dan expects his age will exceed 300 years over time due to the effectiveness of the improved Vitality Seal.
Then Dan came out of the house after making sure everything was fine. As soon as he opened the door, he found all the girls waiting for him in front of the house. They were very worried, their eyes looking at him with fear and anticipation. They had felt that massive wave of energy and then its sudden disappearance, and didn't know what happened. But as soon as they saw him standing before them in good health, they all breathed a sigh of relief, smiled large smiles of comfort, and some had tears of anxiety in their eyes.
Dan looked at them with his calm blue eyes and saw the clear worry on their faces, and the love and fear for him. He felt something warm in his chest; he admired their concern for him and their love despite his coldness and isolation. Then he said in his usual cold voice but with a slightly lighter tone than usual, "I am hungry." Simple words, but enough to bring comfort to their souls.
The girls all smiled quickly—wide smiles full of happiness and relief. They immediately began moving with activity and enthusiasm, heading toward the kitchen to prepare dinner for him. Each one took a role: one cutting meat, another lighting the fire. They talked happily among themselves, very relieved that Dan was fine and that he asked them for something. Dan had become a fundamental pillar in this family, and a simple change in his mood affected the entire atmosphere.
After a short while, the girls prepared a special feast for him: fresh grilled meat, vegetables, and wild fruits. they placed it before him with love and care, and sat around him watching him as he ate, happy just to see him enjoying their food. He ate quietly, for he was truly hungry after eight hours of intense focus and chakra depletion, so he ate more than usual.
After he finished eating, Dan looked at them all and said quietly, "Thank you." It was a simple word, but it meant a lot, especially from a person of few words originally. All the girls' faces turned red with shyness and happiness, and they all smiled. Then he stood up, "I will go to rest for a while," and headed toward his house, feeling satisfied and happy. He had succeeded in taking a big step toward his goal, and that was all that mattered at this moment.