Reviving the Uchiha Clan: Starting with a Legacy of Many Descendants

Sarutobi Asuma drew his signature chakra blades. The blades quickly became enveloped in a blue chakra aura.

Natsuhane remained expressionless. "Asuma, are you really trying to pick a fight with me? Is this necessary?"

"Put the knives away!" Kurenai urged from the side, trying to defuse the situation.

"No! I need to regain my dignity! Kurenai, you said you looked at Natsuhane because he is strong. Today, I'll show you who the real strong one is!" Asuma declared.

With a swift movement, Asuma lunged at Natsuhane, aiming his chakra blade at a sensitive area.

"Damn! That's low!" Natsuhane quickly blocked with a kunai.

"Low? I'm just doing a public service!" Asuma retorted, launching another strike.

"Seriously?" Natsuhane cursed under his breath. His taijutsu was no match for Asuma's, and he knew a prolonged clash would end poorly for him. He quickly retreated to put distance between them.

"What's wrong? Are you scared, Natsuhane? You're not as tough as you seem," Asuma taunted.

"Heh..." Natsuhane chuckled coldly. "Sorry, I'm more suited to breaking a sweat in bed than on the battlefield. I prefer taking the easy way out."

Natsuhane decided it was time to test his Mangekyou Sharingan. Each Uchiha's Mangekyou granted unique, powerful abilities, but Natsuhane hadn't yet discovered his own.

Focusing his chakra, Natsuhane activated his Mangekyou Sharingan. His eyes turned crimson, and the three tomoe spun rapidly, merging into a chilling pattern.

"So this is your Mangekyou Sharingan," Asuma said, feeling a mix of fear and curiosity. He had heard from his father, Hiruzen Sarutobi, about the Mangekyou's mysterious abilities.

Both men stared at each other, neither backing down. Seconds passed, but nothing happened.

Asuma smirked. "Is that it? All that worry for nothing. Your Mangekyou Sharingan is just a myth. Even if you summon that skeletal giant, I won't be afraid!"

Asuma charged again.

"What's happening?" Natsuhane thought, bewildered. His Mangekyou was active, chakra was flowing, yet nothing happened. No Amaterasu, no intangibility, no control over illusions—nothing.

"Damn it, is this Mangekyou a dud?" Natsuhane wondered, recalling the skeletal form of Susanoo he had summoned earlier.

The system's sinister laugh echoed in his mind. "Hehehe... Be patient, boy. You'll see soon enough..."

As Asuma closed in, he suddenly let out a pained scream and collapsed, clutching his stomach.

"???" The onlookers were stunned. Natsuhane hadn't touched him.

Asuma writhed in pain, sweat pouring down his face. "Ugh! My stomach... It hurts so much! Damn it, Natsuhane, what did you do to me?"

Natsuhane raised his hands in mock innocence. "Everyone here saw that I didn't touch you. You're not going to pin this on me, are you? Did you eat something bad, Asuma?"

"Ahhh!" Asuma's face turned white, and he bit his lip until it bled. "Natsuhane, we'll finish this later! Call a medic, now! I can't take it!"

Kurenai rushed to Asuma's side, concern etched on her face. Despite their strained relationship, she couldn't ignore his sudden collapse.

Natsuhane sighed, his mind racing. It seemed Kurenai still cared deeply for Asuma, her childhood friend and destined partner. "Looks like I should back off. They're meant to be together."

Just as he made this decision, Kurenai doubled over, clutching her own stomach in pain.

"What the...!" Natsuhane realized it must be his Mangekyou. His gaze had somehow caused this. Whoever he looked at would suffer.

"Damn, what kind of useless ability is this?" Natsuhane quickly deactivated his Mangekyou, hoping to alleviate their pain.

But even after a minute, neither Asuma nor Kurenai showed signs of improvement.

---

A short while later, medical ninjas arrived, summoned by concerned onlookers.

"Asuma, what's wrong?" one medic asked urgently.

"My stomach... It hurts so much," Asuma groaned, pointing to the sides of his abdomen.

The medics began diagnosing him with chakra-infused hands. Suddenly, one of them looked alarmed. "This is bad!"

Asuma's eyes widened. "What? What's wrong?"

The medic hesitated. "Asuma, it looks like... your kidneys have failed."

"What????"

---

Nearby, another medic was examining Kurenai. She feared she had the same issue as Asuma.

But soon, the medic smiled. "Kurenai, congratulations. You're pregnant."

Kurenai: "What???"

Asuma: "What???"

Natsuhane: "..."

Natsuhane was stunned. Kurenai pregnant? This was too ridiculous.

The system's voice echoed again. "Hehehe... Do you understand your Mangekyou's ability now?"

Natsuhane was still in shock. This was too much.

"Fine, I'll explain. Your Mangekyou Sharingan is unique, influenced by my presence. Its effects vary between genders."

"For men..."

"Left eye: Anyone who looks into it for five seconds becomes infertile."

"Right eye: Anyone you look at for five seconds becomes infertile."

"For women..."

"Left eye: Anyone who looks into it for five seconds becomes pregnant."

"Right eye: Anyone you look at for five seconds becomes pregnant."

"And of course, the child is yours."

"These effects are immediate, causing physical pain—abdominal for men, stomach pain for women."

"And if the targets discover the truth, they'll suffer both physical and emotional trauma."

"In summary: quite the unique ability."

---

Natsuhane was speechless. This was too much. The implications were staggering. Asuma's rage and confusion, Kurenai's shock and disbelief—it all pointed to one undeniable fact. 

This Mangekyou Sharingan was both a blessing and a curse, capable of altering lives with just a glance.