The Fire Style: Great Fireball Jutsu (C-Rank) is a technique that gathers chakra in the throat and releases it in a massive fireball, capable of immense destruction. The Lightning Style: Earth Release (C-Rank) channels electricity through the hands, allowing it to spread across the ground or through water, and its power is greatly amplified when combined with Water Style.

"Sasuke, watch closely. This is Fire Style: Great Fireball Jutsu," Itachi said as he released a gigantic fireball from his mouth.

"Sasuke, observe. This is Lightning Style: Earth Release," Itachi continued, his hands crackling with lightning after completing the seals.

Seeing Itachi perform these two jutsu filled Sasuke with excitement. He couldn’t wait to master them himself. Sensing Sasuke's eagerness, Itachi decided not to tease him further and carefully demonstrated the hand signs, repeating them slowly until Sasuke committed them to memory.

With the sequence memorized, Sasuke eagerly began his attempts. Itachi watched closely, correcting Sasuke whenever he faltered. Though Sasuke managed to perform the techniques, their power was meager.

"Fire Style: Great Fireball Jutsu!" Sasuke shouted, his hands swiftly forming the seals. But the result was only a small flame, barely ten centimeters wide. His first attempt at a C-Rank jutsu ended with his own chakra control burning his hair.

Undeterred, Sasuke pressed on, attempting Lightning Style: Earth Release. He placed his hands on the ground and yelled, "Lightning Style: Earth Release!" A few thin sparks emerged from his palms, dispersing feebly after a meter. Sasuke nodded to himself, noting some improvement, yet he was painfully aware of the vast gulf between his skills and Itachi’s. Itachi noticed his brother’s disheartened expression.

"You’ve done well, Sasuke," Itachi reassured him. "Mastery takes time, even for these C-Rank jutsu. Keep practicing, and you’ll get there." Despite a lingering sense of disappointment, Sasuke heeded his brother’s advice, repeating the hand signs and practicing relentlessly.

Thus began Sasuke’s new training regimen. He never neglected his foundational exercises, believing firmly in their importance. He added ninjutsu practice to his routine, along with chakra training. The sun climbed to its zenith as Itachi stood by, smiling as Sasuke pushed himself. Whenever Sasuke made a mistake, Itachi was quick to correct him. Sasuke’s voice echoed the now-familiar incantation once more.

"Fire Style: Great Fireball Jutsu!" With a triumphant shout, Sasuke finally unleashed a formidable fireball.

"Ha! I did it!" Sasuke laughed with joy, having finally succeeded after countless attempts.

But his triumph was short-lived as he suddenly collapsed, his face buried in the soft grass. Luckily, it was grass and not stone, or his adorable face might have ended up as a bruised mess. Sasuke wondered if he had simply exhausted his chakra and stamina from training too hard.

Seeing him fall, Itachi rushed over, gently lifting him and helping him sit on the grass. Sasuke gasped for breath, nearly suffocated by his own exertion.

"You mustn’t push yourself so hard again," Itachi said sternly. "Always keep enough chakra and strength in reserve, even if you need to escape."

"Okay," Sasuke replied absentmindedly, his mind still preoccupied with his chakra problem, paying little attention to Itachi's words.

Noticing Sasuke's distant expression, Itachi knew his brother wasn’t listening. He decided to save the lecture for later, after all, Sasuke was his beloved little brother. Itachi carried Sasuke home, thinking about how Sasuke was already worrying about his chakra reserves.

"Damn it," Sasuke muttered to himself. "When I only knew the basic techniques, my limited chakra was enough. But now, with these jutsu, my chakra is completely drained. I have to find a way to increase it."

"How frustrating, my chakra is only slightly more than that of a low-ranking ninja," he grumbled. Most would consider it remarkable that a three-year-old had chakra exceeding a typical Genin, but Sasuke was unsatisfied.

"What should I do? Chakra is the key to becoming stronger!"

"I envy Naruto. With the Nine-Tails' limitless chakra, he never has to worry during a fight," Sasuke mused. "Should I seal a Tailed Beast inside me too? That way, I’d never run out of chakra again." Sasuke's thoughts were bold indeed.

"Ha, I'm daydreaming," he scoffed at himself. "Not only would I need to defeat a Tailed Beast, but they've all been sealed away. And being a Jinchuriki is no blessing—just look at how Naruto and Gaara are treated. They’re feared, treated like weapons, not people. Gaara doesn’t even know why he should keep living."

Sasuke quickly dismissed the idea of sealing a Tailed Beast. Instead, he decided to ask Itachi if there was a better solution.

Returning from his reverie, Sasuke realized he was being carried by Itachi, who was walking along the bustling streets towards home.

"Brother, my chakra is too low. I can barely manage one or two jutsu before it’s gone. Is there a way to increase it?" Sasuke asked.

"Sasuke," Itachi replied thoughtfully, "chakra is composed of two elements: physical energy drawn from every one of your 130 trillion cells, and spiritual energy, cultivated through training and experience. Right now, you haven’t yet accumulated the spiritual energy that comes from extensive training and experience, so your chakra is primarily derived from your physical energy. But you’re only three years old—your body hasn’t fully developed. The fact that you can produce chakra at the level of a Genin is already a miracle. To increase your chakra, you’ll have to wait until your body matures naturally."

Hearing this, Sasuke understood that the conventional path wouldn’t allow him to increase his chakra quickly. He would have to find an alternative method. He resolved to figure it out once they got home.

As Itachi carried him through the lively streets, Sasuke watched the people passing by, wondering to himself, "I wonder what the future holds for us. Will we be enemies, or will we stand together?"