"As expected of the ninjutsu created by Uchiha Madara!" Asta exclaimed, eyes gleaming with awe. Though he came from a world without magic, he had now stepped into a reality where ancient shinobi arts existed—and he was mastering them one by one.
He turned his attention to the next entry in the system's scroll.
"B-rank space-time ninjutsu: Flying Thunder God Slash!"
This was a powerful technique developed by the Second Hokage from another world—a variant of the original Flying Thunder God Jutsu, combining instantaneous movement with a deadly sword strike. It used a marker seal, allowing the user to teleport instantly to the marked location and land a critical blow with a katana or blade. For someone like Asta, who wielded the massive Demon-Slayer Sword, it was an ideal pairing.
"This is a perfect match for me and the Sword of Demon-Slaying!" Asta's voice trembled with excitement. His anti-magic already made him a nightmare for mages in the Clover Kingdom, but with this kind of speed-based space-time ninjutsu? He was becoming untouchable.
"Ding! Successfully exchanged: B-rank space-time ninjutsu · Flying Thunder God Slash – 50,000 points spent!"
Flying Thunder God Slash
Imbue any object or person with a space-time seal through direct contact. Once sealed, the user can teleport to the marked location.
Once activated, the user moves instantaneously to the location and executes a precision strike, usually with a blade.
Seals are permanent once marked and cannot be erased without the user's intent.
"Three variations detected," the system continued.
First Form: Blade Rush
Combining the Flying Thunder God mark with a katana or large blade, the user discreetly marks the enemy during close-range combat. Once marked, they teleport directly to the target and pierce through with lightning-fast speed. Ideal for silent takedowns and high-speed finishers.
"That's a lethal assassination move…" Asta thought. But against mages who don't fight up close? Probably less effective. Still, if they let me get close, they're done either way."
Second Form: Kunai Ambush
Throw a kunai imbued with the Flying Thunder God seal toward the enemy. When the kunai reaches their blind spot, teleport behind them and strike with the kunai in hand.
"Now that's just like the Fourth Hokage!" Asta grinned. In his world, they had nothing like this. "Minato's teleportation was so cool, and now I can actually use it?"
Third Form: Diversion Combo
Use both kunai and the sword—throw a marked kunai as a distraction. When the enemy focuses on the flying weapon, teleport to their front using another pre-set seal and land a sword strike directly to the chest.
"Too cool!" Asta couldn't hold back. He quickly pulled out a handful of kunai from his dimensional pouch, infused them with the Flying Thunder God seal, and hurled one toward a distant tree.
"Whoosh!"
In an instant, he triggered the seal—his body vanished, reappearing by the tree.
"Haah!" Asta slashed down with his massive Demon-Slayer Sword. The enormous blade cleaved the thick tree trunk clean in two.
"This is insane!" He laughed, watching the pieces collapse with a thunderous boom.
With the basics now second nature, Asta began experimenting.
Combo Set 1: Flying Thunder God Slash + Fire Release: Majestic Destroyer Flame
Asta hurled a marked kunai behind a rocky cliff, teleported in a flash, then roared, "Fire Style: Majestic Destroyer Flame!"
A wave of blistering fire erupted from his mouth, incinerating the boulder and scorching the air. Though he lacked magic, his hybridized chakra-infused combat style gave him elemental options.
System Note: Anti-magic body + foreign chakra = stable hybridization. Caution: May cause exhaustion.
"This would destroy a whole enemy squad," Asta muttered, breathing heavily from the exertion.
Combo Set 2: Shadow Clone Technique + Flying Thunder God Ambush
Asta created nine shadow clones, each tossing a kunai toward the enemy. Only one kunai was actually marked.
"Try finding the real one!" Asta smirked. His clones vanished in a blur as he appeared behind the target in a blink, blade drawn.
The distraction and the speed made the move nearly unavoidable.
"I've grown way stronger… terrifyingly stronger." Asta clenched his fist. With the Three-Tomoe Sharingan granted by the system—another technique he never imagined possessing—his vision was clearer than ever. It was like shifting from blurry vision to crystal-clear high definition. He could see the world in sharp, calculated detail.
After hours of refining techniques, Asta returned to the Black Bull hideout, a massive crumbling base where his chaotic squad resided. He passed Magna and Luck sparring, nodding to them with a grin.
****
The Next Day – Before Dawn
The forest around the castle was still cloaked in darkness. Asta, already awake and dressed in his training clothes, stepped into the clearing where he'd built his own personal training ground.
Wooden stakes lined the area for striking drills. Targets for kunai were set up in the trees. A crude set of horizontal bars and a climbing frame stood nearby.
"Still missing something heavy…"
Asta walked into the woods, his Sharingan glowing faintly red in the low light. It took him only minutes to find a massive boulder, shaped almost like a cube. It weighed several tons.
"You'll do just fine."
With a kunai in hand, he etched away the sides with chakra precision, shaping it into a more perfect cube. Once done, he hoisted it onto his shoulder—no chakra, just raw strength.
Step by step, he returned to the clearing. His muscles burned, but Asta only grinned through the pain.
"BOOM!"
The boulder slammed down.
He wiped sweat from his forehead, then dove into his routine.
Punches. Thousands of them.
Not full power—his strikes would destroy the stakes. But his form and consistency were perfect.
Kunai throws.
Each landed bullseye, no wasted motion.
Pull-ups. Dips. Jumps. Core.
When the sky finally brightened with the dawn, Asta stood at the center of his clearing, panting but proud.
"This is the strength I need… to protect everyone."
And with a new power from another world coursing through him, he was ready for whatever came next.
"It feels so good to stretch out your muscles and bones!" Asta said cheerfully, shaking his limbs before heading toward the Black Bulls' bathhouse. He still liked calling it that, even though it was really just a hot spring they all shared—and trashed regularly.
After a refreshing shower and a quick change into dry clothes, Asta made his way to the cafeteria, stomach growling.
The door creaked open, and there she was—Charmi Pappitson—already digging into her food with the passion of a thousand hungry wolves.
"Good morning, Asta!" Charmi chirped, her eyes sparkling with joy. Food was her one true love, after all.
"Hey, Charmi," Asta grinned, feeling playful. "Wanna make another bet?" He winked mischievously.
"Ehh? Another bet?!" Charmi's eyes widened, remembering the last one that had cost her her beloved snacks. "N-No thanks!" she yelped and dashed out, her plate somehow still in hand.
"Haha!" Asta laughed. "Still so easy to tease."
"Hmph. Teasing a girl first thing in the morning? Typical." A voice came from behind him—Noelle Silva, arms crossed, pink eyes glinting with something like jealousy. She walked over with her usual grace and attitude.
"Hey, I was just joking. You look great today, by the way," Asta said with a genuine smile.
"Hmph. Of course I do," Noelle replied, sitting beside him without hesitation. Despite herself, she felt lighter around him, especially after everything they'd been through recently.
"Wanna train together later?" Asta offered. Their training grounds were side by side, and he'd even set up a few new bullseyes for her to practice water magic precision.
"For the sake of your enthusiasm, I suppose I could allow it," Noelle said, trying not to sound too eager.
"You two sure have a lot of energy this early in the day," Vanessa Enoteca, said with a yawn as she flopped onto the table, her usual wine bottle in hand.
"Hey, drunkard lady, you're actually eating breakfast?" Magna Swing barged in with Luck Voltia right behind him, both looking unusually alert.
"Yup. Starting the day off right," Vanessa smirked.