Naruto : The ultimate Troublemaker

As they discussed medical techniques and Shikai's impressive Shikai abilities, the latter asked an innocent question that betrayed his constant thoughts:

"Aunt Tsunade, how do you manage to boost your chakra monstrously when you need it?"

Tsunade narrowed her eyes, crossing her arms as if hesitant to share a secret. Then she pointed to her forehead.

"This seal you see there, the *Sōzō Saisei*, allows for the accumulation of chakra over years, which can then be released when needed."

Intrigued, Shikai insisted, "Show me how to create it."

"I could probably improve it," he thought.

Tsunade burst into laughter.

"Listen, kid. This seal is not something you can learn in a week, or even a month. It takes years of discipline to accumulate enough chakra. And frankly, at your age, you don't have enough yet for it to be useful."

Shikai merely nodded, but an idea had sprouted in his mind.

...

Months had passed since Shikai entered this strange world, and his rise in ninja arts was meteoric. His days were packed: fuinjutsu training with Kushina whenever she was available, hiraishin exercises with Minato whenever he had a free moment, and lessons from mysterious ANBU when the Hokage was occupied.

Shikai had his suspicions about the identity of one of these ANBU, especially the one wearing a dog mask who seemed to wield raiton and suiton with disconcerting ease.

"Kakashi... you can't fool me, you have at most fifteen techniques. Fucking chakra-less fraud," he thought during each session.

Beyond these intense trainings, Shikaku Nara regularly imparted him with secret clan techniques, including B-rank and A-rank jutsus, impressed by Shikai's ability to master shadows and improvise complex strategies despite his young age. This earned him the affectionate nickname of "little prodigy" within the clan.

*Two years later...*

Shikai was now five years old. Besides attracting the attention of old Hiruzen, who had met him ten times in a month to talk about the Will of Fire, and some Root members watching him from the shadows—it was logical, as he was the disciple of the Yondaime, learning hiraishin—his days were still filled with training and interactions with the village's key figures. Yet, things were changing. He saw Itachi less and less often, as the young Uchiha was now engrossed with the Academy and the growing pressure from his clan.

Kushina, on the other hand, beamed with radiant smiles and overflowing energy, despite her advanced pregnancy. Naruto was about to be born, and Shikai couldn't help but feel a twinge in his heart every time he saw her. He knew that fate had a tragedy in store for her.

A few days after Sasuke's birth, Shikai observed Kushina and Minato chatting joyfully in the garden. They laughed, happy and carefree, as if the future still belonged to them. Yet, Shikai, with his knowledge of the canon, knew that this peace was but a calm before the storm.

In his room, Shikai scribbled new seal designs on a scroll, his mind tormented by the decision of whether to save them and risk changing the future or leave them as they were.

"There's not much time left. Minato-sama... Kushina-sensei..." he sighed.

"Well, at least I'm done with that." He said to himself with a smile as he stood up.

Thanks to his talent, Shikai had quickly mastered a wide range of techniques, based solely on his ninja skills. He was already at the level of a Jonin, with exceptional chakra control, A-rank Nara techniques, B-rank water and lightning release techniques, not to mention fuinjutsu, the mystic palm he learned from Tsunade, and the hiraishin he could use at short range. But the crucial problem he faced was chakra. His glaring lack of it prevented him from using 3/4 of his techniques in combat.

So, he tried modifying the soldier pills that the Nara clan produced for the Akimichi clan. It was certainly a great success, earning him respect from other clans. But he was not satisfied.

Should he wander onto the battlefield with a bag of scrolls full of pills on his back, only to eventually die by a certain dog? Never. He had asked Aunt Tsunade about it, but her method would take years and was more focused on regeneration.

Shikai was still pondering how to solve this problem. It was true that he would have more chakra as he grew older, and his chakra was already comparable to that of a Chunin, which was enormous. Still, it was not enough for him.

Shikai, bare-chested, sat in a lotus position, opening the scroll he had been writing on in front of him. He quickly took two yellow soldier pills he had improved, which had fewer side effects.

In a matter of seconds, he performed about thirty mudras, making a small cut on his wrists that fell onto the scroll. His chakra exploded, seemingly binding with the technique on the scroll, which appeared more like juinjutsu than fuinjutsu, but Shikai didn't care.

"Let's begin!"

Instantly, a wave of power surged through his body. He then started a series of complex mudras, so fast that his hands seemed blurred. Finally, he slightly cut his wrists, letting his blood fall onto the scroll.

His chakra exploded in the room, radiating suffocating heat. The writings on the scroll illuminated, seeming to come alive like crawling snakes. The air filled with the smell of burning flesh, tearing a groan of pain from Shikai.

"Damn... it hurts..." he growled through clenched teeth.

Through the fuinjutsu Shikai had learned and his divine wisdom, he had developed the technique: *Pentagonal Stigma Seal*.

This technique would allow him to store unique chakras and nourish them, and then he could use them as his own by unsealing the seal. In this way, there was no risk that he would no longer be able to use this type of chakra, as the seal was closer to a form of Code's White Kama.

The marks began to appear on his body, each forming with atrocious pain that seemed to tear his meridians.

There were a total of five crosslet fitchy-shaped stigmata, each already with its role.

Yang Stigma, to absorb and nourish Senju and Uzumaki chakra. A cross located on the fifth cervical vertebra.

Yin Stigma, to manipulate Uchiha and Yamanaka chakra. On the thoracic vertebrae.

Moon Stigma, to contain Hyuga and Toneri chakra. On his left arm.

Jūbi Stigma, a receptacle for Bijū chakra. At the center of his chest.

Sage Stigma, for Senjutsu. In the middle of his forehead.

With each appearance, Shikai felt his muscles contract and his body tremble as if he were about to implode. The pain was so intense that he bit his own wrist to avoid screaming.

When the crosses were finally engraved on his body five hours later, he placed his trembling hands on his wounds and used the Mystic Palm to close them. His breath was short, his face pale. Exhausted, he murmured:

"It took much longer than expected. Fortunately, I had set up a seal to prevent chakra leaks..."

With half-closed eyes, he stumbled to his bed and collapsed onto it, utterly spent.