Kushina and Minato exchanged concerned glances, the calm atmosphere vanishing in an instant. Kushina hurriedly moved to support Renjiro, gently laying him on a nearby futon.

Kushina's concern deepened as she observed Renjiro unconscious on the futon, the unintended consequence of using an advanced chakra drain seal instead of the basic one she had initially planned. She bit her lower lip, contemplating the potential ramifications of her mistake.

"What just happened?" Minato questioned, his brows furrowed with worry.

"Minato, this wasn't supposed to happen. I must have grabbed the wrong seal," she confessed, her tone carrying a mixture of regret and anxiety. "I wanted him to experience a basic chakra drain seal, not this advanced one."

Minato, recognizing the gravity of the situation, approached Renjiro and quickly removed the seal from his hand. 

"Kushina, we need to find a way to stabilize him. His chakra flow seems disrupted. He is only a genin, so we can't let him endure unnecessary strain on his chakra reserves, especially from such a powerful seal. "

Kushina nodded. "I'll try to counteract the drain with a stabilizing jutsu. We need to restore his chakra balance before any lasting damage occurs."

Kushina put some of the medical ninjutsu that she had learnt to use. It wasn't much but after concentrated effort, she managed to stabilize Renjiro's chakra flow, alleviating the chakra drain that had left him in a state of exhaustion. 

"I should have double-checked," Kushina sighed, a tinge of self-criticism in her voice. 

Minato placed a reassuring hand on Kushina's shoulder. "We all make mistakes. What's crucial is that we learn from them. Renjiro will be fine; from the little I know, he's resilient."

========

Renjiro groggily opened his eyes, finding himself on the futon. A dull throbbing sensation lingered, and he could sense the remnants of fatigue in every muscle of his body. Slowly sitting up, he looked around, slightly disoriented.

'Why Am I in so much pain?' It took a moment before Renjiro remembered everything that happened before he passed out.

"What happened?" he asked, his voice betraying a mixture of confusion and concern.

Kushina, sitting nearby, turned her attention to Renjiro. "You experienced the effects of an advanced chakra drain seal, Renjiro. It wasn't intentional. I meant to show you a basic chakra drain seal, but I mistakenly used the advanced one."

Renjiro frowned, rubbing his forehead as if trying to shake off the remnants of discomfort. 

"Chakra drain? No wonder I feel so tired."

Minato, who had been standing by, spoke reassuringly. "It was a mistake, Renjiro. Kushina did her best to stabilize your chakra flow. You'll recover soon enough."

Kushina nodded, emphasizing her apology. "I'm sincerely sorry, Renjiro. It was an oversight on my part."

Despite the unintended consequences, Renjiro managed a weak smile. "It's okay, Sensei. It just caught me off guard. But how does the seal work?"

Kushina decided to shed light on the specifics of the chakra drain seal. "The mechanism behind chakra drain seals is quite fascinating," she began. "Essentially, it involves using your own chakra to control the draining rate of your target. The more advanced the seal, either intermediate or advanced, the more control you have over this process."

She continued, "In the case of the seal I used on you, I thought it was just a basic one, so I didn't initiate the control aspect of it. That's why it drained your chakra so drastically. My apologies for the unintended consequences."

Renjiro, although initially shocked by the unexpected intensity of the seal, appreciated the explanation. 

'It's actually a good seal. The only shinobi who could survive this are maybe Jinchurikis and other S ranked ninjas. Wait, I'm getting all this wrong. Since they could alter the control to more or less depending on their preference, it means that what I experienced was only the default rate. 

Since I'm still a genin, with my chakra reserves nearing chunin or at least I think they are, maybe even Elite Jounins have a chance of surviving this. This is a foolproof method of subduing enemy ninjas. But why isn't it widespread or even possible in the anime? There must be a catch.'

"Kushina-sensei, I'm impressed by how effective this chakra drain seal can be. But why isn't this widely used or taught if it holds such potential?"

Kushina leaned back, reminiscing about her journey into the depths of fuinjutsu. "Renjiro, I first encountered the chakra drain seal when I was just a young kunoichi back in Uzushiogakure. The method I learnt, however, was a bit unconventional compared to the standard chakra ink and paper done here in Konoha."

She continued, "Back then, we used our own blood to inscribe the seal. It was a more intimate connection, and the process required a deeper understanding of one's own chakra. It was a difficult and personal experience, but it allowed for a level of efficiency that the chakra ink and paper simply couldn't compare to. Even the chakra ink was invented as an attempt to replicate the effects we get using our blood. This was after other villages discovered that our blood was a bit special."

Renjiro's eyes widened at the revelation. 'Using blood. The only jutsu I remembered that needed one's blood was the summoning jutsu. Although I read something similar in another fandom wiki.'

"I later transitioned to the standard chakra ink and paper method, as it's more widely accepted and less... well, messy," Kushina said with a chuckle. "But the essence of the technique remains the same. It requires finesse, control, and a deep understanding of chakra dynamics."

Kushina continued, "In recent times, with the increasing demand for fuinjutsu, I've been working on recreating some of the sealing techniques I knew and adapting them so that they now use the conventional chakra paper and ink."

"While I've made progress, it's a challenging task. Some aspects of the original techniques are lost in the process, but I believe it's essential to adapt fuinjutsu to the needs of the current and following generations."

Kushina continued her explanation, "The chakra drain seal you experienced, Renjiro, was meant for more than just draining chakra. But now since I am still adapting the techniques to the common methods, it has lost some of its effects."

"But sensei, what's so special about the Uzumaki blood?" Renjiro asked as he needed to ascertain the effects of the Uzumaki bloodline and pray that he inherited them from his late parents.

Kushina chuckled at Renjiro's question, recognizing the curiosity in his eyes. "The uniqueness of Uzumaki blood lies in its potent chakra and its inherent vitality. Uzumaki clan members, like myself, possess an extraordinarily rich life force and an affinity for sealing techniques. Our chakra is robust and resilient, making it ideal for intricate and powerful fuinjutsu."

She went on to explain, "The Uzumaki's proficiency in fuinjutsu has been a legacy passed down through generations. It's not just about the blood; it's the knowledge and experience handed down within the clan. Techniques that were once exclusive to our clan have been refined and shared with the broader shinobi world."

As for using blood in seals, Kushina clarified, "Using blood in fuinjutsu has a symbolic aspect. It connects the practitioner more intimately with the technique. It's like infusing a part of yourself into the seal, creating a personal link. However, the transition to chakra paper and ink opened up new possibilities for sharing these techniques beyond our clan."

"If you're interested in delving deeper into the Uzumaki's unique approach, I can share some more advanced techniques that were traditionally passed down within the clan. It might give you a broader perspective on fuinjutsu," Kushina offered.

'Yes! That will help a lot I just hope that I also inherited something from the Uzumaki clan other than the unusually high chakra I currently have.'

"But all this would be in due time. You are still not quite ready. Master the normal way then we can move to the Uzumaki way." Kushina said as she placed some seals next to Renjiro.

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