The gears of fate often interlock in the depths of the most inconspicuous ruins.
The night wind, sharp as a blade, whipped up the remaining ashes in the ruins.
This abandoned construction site behind Jujutsu High, having undergone the baptism of the Night Parade of a Hundred Demons, had become a completely lifeless wasteland.
Yoru walked alone through the debris, slowly making his way to the deepest part of the ruins.
Moonlight filtered through thick clouds onto his tattered black trench coat, casting a long, lonely shadow.
Every piece of rubble and every crack here filled him with a bone-chilling sense of familiarity.
"So that's how it is..."
Yoru stopped and looked around at the terrain, a complex, bitter smile tugging at the corners of his mouth.
'No wonder I felt such terrifying cursed energy fluctuations in these ruins when I first arrived.'
"So that residual power that nearly scared me to death back then was actually the aftermath of my own battle against Kenjaku and Satoru Gojo."
The script of fate had completed a perfect closed loop in this unremarkable corner.
Yoru took a deep breath and focused his mind.
He walked to a collapsed supporting pillar, brushed away the thick dust, and began digging into the ruins with his bare hands.
Though his stamina was exhausted from the previous bloody battle, his physical strength remained formidable. In moments, he had dug a hidden, deep pit.
"Clang!"
Yoru slowly drew the blade from his waist.
It was the Special Grade Cursed Tool Shiranui, which had been his companion for ten years and had slain countless powerful enemies.
Now, the once long and sharp katana had a large portion of its blade broken off, and the remaining steel was covered in a web of fine cracks.
It was on the verge of shattering, unable to withstand even the most basic Breathing Technique slash.
Yoru reached out and gently stroked the cold, broken blade, his eyes filled with deep reluctance.
From the moment he forged it in 2006 to 2018 when Satoru Gojo returned it to him, and then back to the past again...
It had witnessed too much blood and too many miracles.
Yoru took out a special ebony cursed tool box from his system space, designed to completely isolate cursed energy fluctuations, and carefully placed Shiranui inside.
"Old friend, you've worked hard."
Yoru whispered softly to the broken blade resting in the box.
"Rest well."
"I will pick you up again in this very same place."
"And then, we will fight side by side once more."
With a crisp click, the box was locked tight.
Yoru placed it in the deep pit, covered and packed it with dirt and rubble, and set a highly concealed illusion technique over it.
Having finished, Yoru stood up and patted the dirt off his hands.
The first step of the Paving Plan, hiding the blade, was complete.
Next came the core and most incredible step.
'System,' Yoru called out in his mind, his dark red eyes flashing with unprecedented intensity.
"Initiate Privilege Conversion Procedure."
[DING! COMMAND RECEIVED.]
[WARNING: THE HOST IS ATTEMPTING TO STRIP AWAY A PORTION OF THEIR CURRENT CORE ABILITIES. THIS OPERATION WILL LEAVE THE HOST IN A TEMPORARY STATE OF WEAKNESS UPON RETURNING TO THE FUTURE TIMELINE.]
[DO YOU WISH TO PROCEED?]
"Confirm."
Yoru did not hesitate for a second.
He knew all too well the desperation his past self felt upon arriving in 2018, facing a mutating Grade 1 Cursed Spirit with only 1% Synchronization Rate!
If not for that Trial Card that seemingly fell from the sky...
He never would have survived that certain-death scenario, let alone gained Gojo's attention and entered Jujutsu High.
!!!"Vwoom!"
Following Yoru's confirmation, a blinding red light erupted from his body!
That light contained the extreme heat of Sun Breathing, the insight of the Transparent World, and the supreme sword intent of Yoriichi Tsugikuni that could sever anything!
Under the forced stripping and compression of the system's rules...
This suffocatingly massive power eventually condensed in Yoru's palm into a card radiating a faint golden glow.
[YORIICHI TSUGIKUNI FULL ABILITY TRIAL CARD (DURATION: 10 MINUTES)]
Looking at this card that couldn't be more familiar, waves of shock crashed through Yoru's heart.
The truth was revealed!
Why had he inexplicably obtained a trump card that could insta-kill a Grade 1 Cursed Spirit when he first arrived?
Why would the system generously gift such a game-breaking starter pack at the most critical moment?
It turns out it wasn't some stroke of luck or fate at all!
It was his current self, standing at the end of this timeline, personally leaving a life-saving charm for his past self!
"I... am my own cheat code."
Yoru gripped the trial card tightly and looked up at the cold crescent moon, letting out a wild, hearty laugh.
What an absurd yet blood-pumping temporal paradox!
He had crossed the river of time and survived countless battles to the death.
Then, he returned to the beginning of the story to plant this power like a seed into the soil of the past.
Karma intertwining, the loop of fate closing.
This was the truth!
Yoru sealed the trial card under an unremarkable stone slab in the ruins, setting a trigger mechanism that would only activate when the past Yoru's presence arrived.
[DING!]
[PAVING PLAN EXECUTION COMPLETE.]
[RETURN COUNTDOWN: 10 MINUTES REMAINING.]
The system's prompt rang out again, its tone tinged with urgency.
Yoru stood silently in the center of the ruins, feeling the space around him begin to distort and repel him violently.
The world line was attempting to forcibly eject him, an anomaly that did not belong to this era.
The legacy of power had been left; the life-saving trump card was in place.
However...
Yoru's brow furrowed, a look of extreme gravity flashing in his deep red eyes.
He knew well that a trial card and a broken blade weren't enough for his newly arrived self to gain a firm footing in this peril-filled, hopeless future.
Kenjaku's schemes, the calculations of the higher-ups, Sukuna's revival...
All these disasters required an absolutely clear strategic guide!
Besides power...
He needed to leave something else.
Something that would allow his newly arrived self to instantly see through the future situation and seize total control amidst the confusion...
The Ultimate Prophecy!
Yoru suddenly bit his fingertip and, using it as a pen, quickly wrote a line of blood-red characters on the back of the stone slab covering the trial card.
It was his final, arrogant declaration to his future self, and to this wretched jujutsu world, before he departed this era!