Sea Calendar, Year 1517...
Within Foosha Village, the seventeen-year-old Ace of this timeline was engrossed in grueling, relentless training.
Watching his younger self from behind his mask, the adult Ace felt a surge of mixed emotions.
Over the past few years, he had stayed hidden around Foosha Village solely to mentor this alternate version of himself. Now, not only had the young Ace mastered both Armament Haki and Observation Haki, but he had even begun awakening his Conqueror's Haki.
In terms of raw talent and foundational strength, this young Ace was significantly more formidable than he had been at the same age.
"Second Master, let's spar!"
Young Ace had two masters: one was the adult masked Ace, and the other was Aoki Shiraishi himself.
"I don't want this kid brainwashed into running off to the Whitebeard Pirates before he even sets out to sea!" Shiraishi had stated flatly back then.
"He was meant to—"
"Let him choose his own path!"
Because of that decision, Shiraishi and Ace had stepped into the role of his mentors, guiding his development without ever revealing their true origins.
Faced with the boy's challenge, the adult Ace scratched his head: "Your skin must be itching for a beating, kid."
"Hmph!"
The moment the words left his mouth, young Ace—fully prepared—flexed his thigh muscles and coiled downward. Springing forward like an agile leopard pouncing on its prey, his explosive speed made the adult Ace nod in silent approval.
Closing in, young Ace flashed a mischievous grin. Snapping his shoulder, he thrust his right arm forward with fingers splayed wide, clawing toward Ace like a bird of prey.
Ace responded with measured calm. Denying him the grapple, he shifted his left side back while driving a crisp right horizontal hammer-punch to intercept the waist-level advance.
Yet the instant their limbs made contact, young Ace's left fist—which had been coiling power all along—swelled with muscle. Reinforced with Armament Haki, it shot out like lightning, striking straight toward Ace's abdomen like a striking viper.
The right-hand claw was a feint; the left fist was the real strike!
This was an offensive combination young Ace had spent days planning!
Ace swung his left arm down in a hurried block. Because the parry lacked full follow-through, he was pushed back by the force of the punch. Had he not tucked his abdomen in time, the exchange would have looked far more awkward.
This little brat... I actually underestimated him!
Dropping his casual attitude, Ace turned serious. Young Ace flipped back several paces and stuck out his tongue: "Second Master, no using your Flame-Flame Fruit powers!"
"I won't use my Devil Fruit."
Just as young Ace twisted his arm to break free of an incoming clinch, Ace planted his foot, sprang forward, bypassed his guard, and slipped directly behind him. Twisting in stride, Ace locked his hands over the boy's slender arms.
With a twist, a lift, and a scissor-lock, Ace completed the grapple. Simultaneously, he drove his right foot against the back of young Ace's knee, attempting to take out his footing.
Anticipating the sweep with his Observation Haki, young Ace drove his head back in a sharp headbutt. As he broke the hold, Ace fired a focused burst of compressed atmospheric shockwaves from his fingertips.
Ace's mastery over Armament Haki emission had advanced considerably over the years, further elevated by the gradual awakening of his Fire Release Sage Body. With that refined control, he easily pinned the young fighter down.
"Not bad. Your strength has improved tremendously compared to before. You're definitely qualified to set sail!"
"Awesome!"
Although history had deviated, Garp remained the grandfather figure to both Ace and Luffy. As a child, young Ace had still met Sabo at the Gray Terminal, becoming close confidants and stealing loot together to save funds for their future pirate ship.
They had crossed paths with Luffy when he tailed Ace, discovering their hidden stash. Though they initially contemplated silencing Luffy to protect their secret, they were ultimately at a loss on how to kill anyone. Following the incident with Porchemy, they came to accept Luffy as one of their own.
After shouting their respective dreams to the ocean, Ace brought out the sake he had stolen from Dadan, clinking cups to seal their brotherhood.
The adult Ace had observed all of these events from the shadows without interfering. When Sabo wrote his farewell letter and stole a small fishing vessel to sail out alone, Ace had initially intended to save him—only to discover that Sabo hadn't died, but had instead been rescued by Monkey D. Dragon.
Standing beside him back then, Shiraishi had remarked calmly: "According to the history I know, Sabo goes on to become the Chief of Staff of the Revolutionary Army."
"Why didn't you tell me that earlier?!"
Over these past few years, Shiraishi had maintained close ties with the Revolutionary Army. The Sky Island Corridor had effectively become the Revolutionary Army's secondary global logistics hub.
With both factions working in tight coordination, the Sunagakure Pirates stood as the Revolutionary Army's primary strategic partner in the New World.
"Since you're setting sail," the adult Ace said, pulling out an ornate treasure chest, "I have a gift for you."
He handed the box containing the Rumble-Rumble Fruit (Goro Goro no Mi) over to young Ace.
"What's inside here...?"
"The ultimate Logia-type Devil Fruit: the Rumble-Rumble Fruit."
Hearing the words ultimate Logia, young Ace's eyes went wide, sparkling with pure excitement as he popped the chest open without hesitation.
"You should understand, though," Ace cautioned, "if you want to become a great pirate, losing your ability to swim might not be worth it..."
While a Devil Fruit provided an immediate leap in combat capability, it was by no means an absolute necessity for someone seeking true freedom across the seas.
Young Ace had already established a solid foundation in all three forms of Haki, meaning ordinary Devil Fruit users posed little threat to him anyway...
"Blegh... This tastes terrible!"
"Hey! Were you even listening to me?!"
Ace was rendered speechless by his younger self's absolute recklessness. All those profound warnings had gone completely in one ear and out the other.
The moment young Ace heard it was the strongest Logia, he had scarfed it down without a second thought.
"Second Master..."
"What is it now?"
"I... I don't think I can control this power..."
Silver-white lightning crackled violently across young Ace's body. As the Rumble-Rumble Fruit took hold, colossal storm clouds gathered across the sky. The boy's entire physical frame began ticking like an unstable time bomb, threatening to detonate at any second.
No wonder Birka had been utterly obliterated by Enel in the original timeline. The raw elemental fury of the Rumble-Rumble Fruit—representing the most violent force in nature—was simply impossible for an ordinary human to regulate upon first consumption.
Damn it! If he loses control here, the entire Foosha Village will be wiped off the map!
Ace had never anticipated the fruit's initial awakening would be this volatile. Even with young Ace possessing refined Haki at seventeen, he was still overwhelmed by the raw elemental surge.
"Honestly... Why on earth did you hand him the Rumble-Rumble Fruit right now?"
Just as the boy was about to go berserk, a beam of frost light descended from the heavens, forming an isolated spatial containment barrier.
Dressed in his silver captain's coat, Shiraishi manifested an absolute freezing domain, locking down the surging electrical radius around young Ace.
Yet inside the frozen seal, young Ace's eyes burned blood-red as the colossal avatar of the Thunder God materialized behind him...
BOOM!
With a deafening detonation, the surrounding ice barrier was shattered by pure lightning!