As they sailed along the Grand Line toward Garp's hometown, nearly every day was marked by intense sparring between Garp and Raidon. They openly displayed the powers of their Devil Fruits—except for Raidon's first Devil Fruit, which he kept secret from the world.
They had been journeying toward East Blue for nearly a month at an incredibly slow pace. Each time they sparred, the ship had to stop, as their battles were too destructive to continue while underway. Both fighters were gradually mastering their Devil Fruits and growing stronger—Garp even surpassing his former peak, while Raidon steadily closed the gap between them.
Their sparring sessions became longer with each passing day. On one occasion, they fought continuously for five days before stopping, during which Raidon managed to hold his ground until Garp's sheer power overwhelmed him. Yet even such monumental clashes had their limits. Eventually, both hit a plateau, recognizing that only a true life-and-death battle could push them further, something neither could offer the other. Still, their routine remained unchanged: sparring after breakfast, again after lunch, and once more until dinner. Only during their rest periods could the warship resume sailing.
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It didn't take long for their scouts to spot the island. Upon learning they were nearing their destination, Garp readied himself, hoisting a large backpack filled with food for Luffy and Ace—some of which Raidon himself had hunted. Twenty minutes later, they docked, and Garp promptly disembarked, Raidon trailing close behind.
As they walked into town, nearly every citizen greeted Garp, thanking him for safeguarding the village. Though not stationed there, his reputation alone kept pirates at bay. Soon, they encountered the mayor: an elderly man in a patterned shirt and cap, leaning on a cane with a snow-white goatee.
"Garp-san, welcome back," the mayor said.
"Ohh, Mayor! How're you doing? No backaches, I hope? Ha ha ha!" Garp boomed, slapping his knee.
"Of course my back hurts. Not everyone's a monster like you," the mayor retorted dryly. Their banter continued until the mayor noticed Raidon quietly observing his surroundings.
"Hmm… Another one of your sons? Seems you're still spry, eh? Heh heh heh," the mayor teased.
Garp waved him off. "Nonsense! We just crossed paths by chance."
The mayor turned to Raidon. "I'm the mayor of this island. If you have questions, don't hesitate to ask."
"Thank you. I'll be in your care," Raidon replied. "My name is Marisvallis D. Raidon. Should trouble arise, I'll assist however I can."
The mayor shot Garp a questioning glance, but Garp responded with a thumbs-up. After a brief exchange, the mayor excused himself to attend to town matters. Once farewells were said, Garp and Raidon resumed their trek toward the mountain.
It didn't take long for them to reach a cabin nestled in the woods. As Garp strode ahead, he abruptly plummeted into a hidden pit, his mood souring instantly. Raidon bit back a laugh at the sight.
After clambering out, Garp marched to the cabin door and kicked it down without knocking, startling the bandits inside. They seized their weapons, ready to attack—until they recognized the intruder.
"Garp?" asked a woman with curly orange hair, clearly the group's leader.
"Oi, Dadan! Is that any way to greet an old friend?" Garp grumbled, eyeing the club still gripped in her hands.
"Old friend? You just smashed my door!" Dadan snapped, her glare met by Garp's unrepentant grin. Their argument volleyed back and forth until Garp cut in: "Where's Ace and Luffy?"
"They're off in the forest. You know how rowdy those brats are," Dadan replied, shrugging.
Garp huffed and stomped outside to search for his grandsons, leaving Raidon alone with the bandits.
"So… who are you? One of Garp's apprentices?" Dadan asked, sizing up Raidon's towering frame and mature demeanor.
"No, I'm not a Marine. Garp found me on an island he visited. He suggested I stay here awhile—help protect the place in his absence," Raidon explained.
"Oh? Are you strong enough for that?" Dadan pressed, skepticism lacing her tone.
"I lasted ten days against Garp before losing. Take that as you will," Raidon said casually.
The bandits gaped. They knew Garp's strength firsthand—a legend even among Marines. Surviving a week and a half against him was no small feat.
Raidon and the bandits just continued to talk, and Raidon also explained how he got so strong to be able to match Garp. He explained his training routine and his daily hunt for sea kings. When Raidon explained his training routine, the mouths of the bandits widened to the point where it was almost reaching the floor, something that made Raidon laugh as it was really an exaggerated gesture, this talk just continued until it reached lunch time.
Garp then came back, carrying two small children full of bruises and bumps, obvious that Garp beat them for a reason, Raidon then recognized one of them as he was wearing a strawhat, the most famous strawhat in his real world.
"These brats have no shame, saying that they would be pirates when I am a marine," Garp said, with his mood irritated.
"Old man, you will not stop me, I will be a pirate in the future," One of the children said, shouting and retaliating at Garp.
"Old man? Call me grandpa," Garp said, while punching that kid in his head once again. The other kid was just laughing before saying to Garp.
"Grandpa, I won't be a pirate in the future," The child wearing a straw hat said, it made Garp happy a little bit before the child continued his sentence.
"I'll be the pirate king HAHAHAAHAHAHA," The child said, while laughing at Garp, who just punched him in the head too like what he did to the other child.
"You, Luffy, you are corrupted by that despicable red hair," Garp said, blaming Shanks for Luffy's current behaviour.
"Don't badmouth Shanks, I owe my life to him," Luffy then replied, shouting at Garp, where Garp was just seething with anger, wanting to punch Luffy, but before they could continue bickering, the one who was already punched by Garp noticed Raidon looking at both Garp and Luffy, curious, he just asked bluntly.
"WHO'RE YOU?" The child asked Raidon, looking up to him as their height did not matched at all despite Raidon just one year older than this child.