In a hidden base deep within the mountains surrounding the Land of Rivers, many mysterious individuals dressed in black robes and wearing silver necklaces with an outer circle and an inner triangle were busily engaged in training.
"Akagi Shinsuke, Hidan, start today's taijutsu training after the blood draw."
"Yes, Lord Taki."
Bang, bang!
In a spacious, slightly brighter secret room, two figures were engaged in an intense taijutsu fight, with the sound of punches hitting flesh ringing out continuously.
One figure was knocked to the ground, only to immediately counterattack the next moment.
As the battle continued, physical strength began to wane, and both combatants' moves became increasingly disorganized, turning the fight into a contest of sheer willpower.
A punch here, a kick there, let's see who would collapse first!
This kind of battle wasn't particularly spectacular or shocking.
These two boys, appearing to be around 14 or 15 years old, were not highly skilled in taijutsu, and their techniques were lacking.
However, judging by their strength and endurance, it was evident that their physical abilities far exceeded the average for their age group.
So, to the black-robed onlookers, even though the fight wasn't remarkable, they continued to record every detail.
After all, this wasn't merely a taijutsu lesson but part of their daily observation and research.
"That's enough for today. Rest for an hour, then proceed to the jujutsu training."
The speaker was a middle-aged man appearing to be in his forties or fifties, dressed in a dark red robe, unlike the others in black robes. He wore a kind smile, resembling a friendly neighbor from the countryside.
In reality, this seemingly kind man was the founder of the cult of the Evil God, Jashin, which preached 'endless slaughter' and secretly expanded its influence while committing mass killings.
Unbeknownst to many, the cult had become a taboo in the Land of Rivers and beyond!
The two boys, ready to punch each other, stopped just centimeters from connecting.
"Tch, you got lucky this time. Next time, I'll smash your head in!"
The gray-haired, purple-eyed boy with a slicked-back hairstyle and a Takigakure headband around his neck glared at his opponent.
If it weren't for his exhausted, bruised, and dusty appearance, his words might have had some weight!
The other boy, with brown spiky hair and a cold expression, matched his opponent in height.
Contrary to his 'frail' appearance, he fought with reckless abandon, almost terrifyingly so.
Those who knew him well would realize this seemingly 'gentle' boy had a vile temper!
As the other started mouthing off, the boy, Akagi Shinsuke, responded calmly, "With your honey-soft punches? If you aim to sweeten me to death, you've succeeded, Hidan."
"Akagi Shinsuke! You bastard, I'll kill you!"
Unable to out-argue his opponent, Hidan's eyes filled with murderous intent.
"How dare you insult my iron fists?! In Lord Jashin's name, you're dead today!"
"Oh, sorry, I shouldn't have said that... after all, you don't cry for your mom when getting hit!"
Akagi Shinsuke stood his ground, even ramming into Hidan's chest, causing him to stagger back, his eyes growing red with rage.
Seeing Shinsuke's 'is that all you got?' face...
Hidan snapped!
"Die!"
With a shout, Hidan pulled out a black short spear and, under everyone's resigned gazes, stabbed it through Shinsuke's heart!
Pffft!!!
Pain!
It hurts so damn much!
Though not his first time experiencing death, the agony of a pierced heart remained unbearable.
As Hidan's spear pierced Shinsuke's heart, Shinsuke's kunai thrust into Hidan's throat!
Shinsuke had anticipated Hidan's move and chose to counter instead of dodge.
He's a man ruthless to others and himself.
Thud...
Both Shinsuke and Hidan fell, one with a pierced heart, the other with a slit throat.
For normal people, such fatal wounds would mean certain death, even with immediate medical attention.
Yet, no one moved to help.
They remained indifferent, recording the event with unemotional expressions.
Moments later, Hidan raised a hand, pulling the kunai from his throat, and stood up, cursing internally at the pain.
"Argh! It hurts, damn it!"
On the other side, Shinsuke revived three seconds after death, pulling the spear from his heart and tossing it aside.
If fate had brought him to this deadly world, he must adapt, kill, or be killed!
Spitting blood, Shinsuke taunted, "Is that all? My grandma hits harder!"
Hidan ground his teeth in frustration but couldn't deny the truth.
Both had gained a form of [Immortality] from surviving the ritual, a gift from the Evil God!
This wasn't the first time Hidan killed Shinsuke in anger, only to face retaliation.
Their feud had become a source of valuable data for the cult.
"End the petty game, kids. No rest; head to Room 2 for the next session."
Taki, the cult leader, finally spoke, having enjoyed the show.
Their rivalry had provided ample research material, each encounter recorded meticulously.
Understanding the futility, Hidan begrudgingly obeyed.
This rivalry had gained Shinsuke a fearsome reputation within the cult, despite his outwardly frail appearance.
Thus, their feud continued, monitored, and recorded, each clash adding to the data collection and driving the cult's sinister experiments.