Naruto: I Can Upgrade My Techniques Infinitely-Chapter 69: Great Dragon Fire: Level Up!

[Perpetual Lock-On]: Your Fire Style: Great Dragon Fire Jutsu now has homing capabilities, making it much harder to evade.

[What? Poison-Poison Fruit? Wrong Universe, Buddy]: Your Great Dragon Fire now consumes 15% more chakra. Targets will randomly suffer a temporary plague effect until the jutsu hits or dissipates.

[Great Dragon Fire, MEGA EVOLVE!]: Your Great Dragon Fire becomes a Nine-Headed Dragon. Area of effect massively increases.

"...Huhhh," Nara Kazuki's expression twisted.

He'd expected a straightforward upgrade—maybe something like the one for Great Fireball Jutsu—but instead, he was looking at a wild selection.

Luckily, this time his choice was easier. The first option was decent: a homing fire dragon was definitely more annoying to dodge. But it still wasn't a guaranteed hit. So Kazuki discarded it immediately.

The second one... that was interesting.

The chakra cost went up by 15%, sure—but it inflicted a random plague status effect on the target, lasting until the jutsu either made contact or vanished.

What did "plague" even mean here? Probably mild stuff: fever, nausea, vomiting... maybe bloody urine if the system felt like being spicy. But still—15% more chakra for a random debuff?

Then Kazuki realized something:

The effect lasted until the jutsu hit or disappeared.

He stared up at the sky, formed hand seals, and launched a Great Dragon Fire into the air. Then he silently counted.

Seventeen seconds before the fire dragon fizzled out in the clouds.

Seventeen full seconds of status effect.

He didn't even need to aim at the enemy. He could just throw it above them and let the debuff ride. For seventeen whole seconds, they'd be afflicted by who-knows-what.

The image of Uchiha Obito clutching his stomach in agony, diarrhea threatening to escape mid-fight, flashed into Kazuki's mind.

He almost burst out laughing.

"Sorry, MEGA evolution. If not for that plague option, you'd be my pick," Kazuki sighed wistfully.

If it were any other time, he would've loved to see a nine-headed fire dragon torch a battlefield. But this time? No contest.

He wanted to watch Obito shit himself in battle.

It wasn't that Kazuki hated Obito at first—but once he saw that defeating Obito could unlock special Rewind Achievements, the man became an unavoidable stepping stone.

To grow stronger, Kazuki had to make Obito suffer.

Having chosen his upgrade, Kazuki was giddy with anticipation. Time to test it.

First thought: Kakashi. But Kazuki quickly dismissed it. He didn't want to mentally scar the man with explosive diarrhea. Not yet, anyway.

"Practicing Great Dragon Fire again?" came a gravelly voice.

Kazuki turned around. Sure enough, it was Sarutobi Hiruzen.

He immediately straightened and greeted the Third Hokage with respect.

"You can't release multiple fire dragons yet?" Hiruzen asked, watching him with amusement.

Kazuki shook his head honestly. "Not yet, Lord Third. I'm getting closer—I can almost form one and a half. But two? Still working on it."

Hiruzen didn't seem disappointed. He already knew Kazuki wasn't a prodigy. If he were, he would've stood out long ago—not just sat in the ranks as a chūnin.

"Come," Hiruzen said with a chuckle. "Let this old man give you a few pointers."

"Uh... Lord Third, are you sure?" Kazuki hesitated. He'd just taken the plague debuff upgrade. Was it really okay to use the Third Hokage as a live test subject?

"It's fine. I'm just an old man now. Helping Konoha's future talents is a joy," Hiruzen replied kindly.

Kazuki tried to refuse, but the old man insisted. So the two headed to a secluded training ground.

"Show me your Great Dragon Fire," Hiruzen said warmly.

Kazuki took a deep breath and began weaving hand signs.

Hiruzen squinted.

Strange. This brat usually casts so fast it's like a flex. Why's he suddenly going slower?

Whatever. He was here to teach, not to judge.

But the moment Kazuki finished casting, Hiruzen's eyes widened.

An intense nausea slammed into him—like a sweaty taijutsu user had pulled off their rank socks and used them to rake the back of his throat. His stomach churned. His throat clenched. His vision spun.

Kazuki's fire dragon blazed toward him.

But Hiruzen wasn't a former Hokage for nothing.

In a flash, he launched Water Style: Multiple Water Dragon Bullets, dozens of serpentine torrents smashing into the fire, dousing it mid-air and obscuring Kazuki's view.

When the mist cleared, Hiruzen was standing there with a forced smile. The ground beneath him was soaked.

"Lord Third, are you alright?" Kazuki rushed over, concerned.

To his relief, Hiruzen didn't stink, nor did he show signs of leakage.

Thank god it wasn't diarrhea, Kazuki thought. That one's a nightmare to hold back.

"Ahem. I'm fine. But your Great Dragon Fire..." Hiruzen cleared his throat with exaggerated calm, hiding the fact that his voice still felt raw.

He began offering technical pointers—how to control the fire stream, how to balance chakra distribution mid-cast.

Kazuki listened intently. To his surprise, Hiruzen's advice made a lot of sense.

Then Hiruzen said, "Try again."

Kazuki blinked. "Wait, are you sure you want me to aim at you again?"

The old man nodded confidently. That sick feeling was probably just indigestion.

Kazuki gave him a doubtful look—but obeyed.

This time, Kazuki incorporated the advice and successfully cast two fire dragons simultaneously.

They roared forth—and Hiruzen immediately regretted everything.

His stomach flipped. His gut rumbled. His vision dimmed. It felt like a spiritual food poisoning.

What the hell—did I catch a gastrointestinal flu from his chakra?