Fierce Battle on the Island

“Roar…”
“Roar…”
No sooner had he stepped into the jungle than countless deafening roars erupted across the entire island.
Xuan Ye narrowed his eyes, his expression tense, for in those roars he could feel a tangible pressure.
The endless forest seemed a radiant black hole, not only stretching on without end, but also brimming with countless deadly dangers.
Crack. Xuan Ye halted, every hair on his body standing upright as his Observation Haki spread rapidly, yet he found nothing amiss.
Yet his intuition told him he was being watched.
“My Observation Haki is still too weak.”
Standing still, Xuan Ye realized his ability was of no use, so he resorted to sight, slowly shifting his body as he scanned his surroundings. At last, he spotted something unusual.
In the jungle to his left, a pair of blood-red eyes stared at him with ferocious malice.
“Roar…” Deafening, visible to the naked eye; with a single roar, the grass before him was swept away, revealing moist, fresh earth beneath.
Menacing fangs, needle-like whiskers, powerful limbs, terrifying claws, and a thick tail—all spoke to the creature’s immense strength.
Most crucially, this beast radiated a peculiar bloodlust, a pressure that made Xuan Ye deeply uncomfortable.
“Astonishing—barely on the island and I’ve already met one rivaling a lieutenant colonel. This truly is a fine place. Well, let them all become my stepping stones.” Muttering to himself, Xuan Ye took the initiative, his body blurring into a shadow, kicking up dust as he shot toward the beast like a cannonball.
“Roar…”
With a roar, the beast opened its huge maw, gleaming teeth bared, and lunged at Xuan Ye without hesitation.
Boom! A burst of air erupted, and Xuan Ye’s eyes widened—this monstrosity could actually predict his attacks.
“Armament: Fire Claw.”
Involuntarily, Xuan Ye spread his fingers, invisible Haki and flames swirling around them, and struck fiercely.
Boom—sand and earth exploded. After the blow, Xuan Ye darted back, his expression grave.
“Roar…” A low roar as the beast shook its head, unharmed, and charged at Xuan Ye once more.
“This blow would have flattened any ordinary lieutenant colonel. Looks like I’ll need to show some real skill.”
“Soru…”
Boom! Bang!
Sand flew, air blasted, man and beast engaged in raw hand-to-hand combat, a fierce and primal battle.

Xuan Ye did not use his Devil Fruit abilities, relying solely on physical techniques, his fists landing solid blows, treating the beast as a sparring partner.
Minutes passed.
“Huff… huff…” Heavy breaths; his shirt had long since become strips of cloth, and savage red wounds snaked across his body.
Opposite him, the beast was barely breathing, its body reduced to a heap of shattered bones and rotten flesh.
Recording his progress, Xuan Ye pressed deeper into the jungle, excitement growing. From the recent fight, he realized he was improving—not by leaps and bounds, but genuine progress nonetheless. Battle truly was the best path to breakthrough.
Time slipped by like sand; Xuan Ye had lived on the island for a week now. At first, he relied solely on physical combat, not aiming to slaughter beasts, but to spar. Clearly, from his aura alone, he was now a different person from before.
“Roar…” An unwilling bellow; a colossal creature, like a small mountain, collapsed weakly to the ground.
Atop its head, a young man with short, tousled hair, bare-chested and covered in scars, panted lightly.
“Huff… The deeper I go, the stronger they get?” Sitting down, Xuan Ye wiped cold sweat from his brow—for this monster had fought him for a full hour, nearly forcing him to use his Devil Fruit.
“No, it’s too dangerous here. Night is coming. I’d better find a place to rest.”
That first night, unfamiliar with the circumstances, Xuan Ye was targeted by a pack of beasts and nearly lost his life. Had he not used his Devil Fruit, he might have failed then and there.
For night here was far more terrifying than day.
Just as he was about to rise, Xuan Ye tensed, gaze fixed on the sky, where a black dot was plummeting like a meteor.
“Unlucky—now a bird of prey has set its sights on me.”
Judging by size, this monstrous bird spanned nearly thirty meters, and its razor-sharp beak and talons put Xuan Ye on high alert.
“This aura—almost at vice admiral level.” His face darkened, and he activated his abilities, fearing that if he didn’t, he might not get another chance.
Whoosh—endless flames roared skyward, instantly turning the surrounding hundred meters into scorched earth.
“Infinite Arrows.” Flames erupted, and behind Xuan Ye, nearly forty blades, spears, swords, and halberds surged upward like a torrent, shooting toward the heavens.
Screech! With an eerie cry, the giant bird’s talons turned pitch black and swooped straight at Xuan Ye, ignoring his attacks entirely.
Boom! Its enormous wings unfurled, creating metallic sounds as Xuan Ye’s assault was rendered void.
“I…” Xuan Ye’s pupils contracted, and in a flash, his figure appeared a hundred meters away.
Just then, the ground shook, rocks flew, earth cracked, and the giant bird circled within a massive pit, its ferocious eyes locked onto Xuan Ye.
“Hmph… Let’s see who is stronger.”
With a cold snort, Xuan Ye saw disdain and provocation in the beast’s gaze.
“High Heat: One Hundred Thousand Degrees Celsius.”

Boom! Heat waves erupted, smoke billowed, the entire space convulsed as Xuan Ye’s body blazed with golden-red flames, a gigantic bird faintly forming behind him, wings outstretched.
This temperature was Xuan Ye’s current limit, but he believed that one day his flames would burn all things.
Unbeknownst to him, the earth beneath his feet had already begun to melt into a liquid.
Screech! With an explosive cry, Xuan Ye struck first, his eyes ablaze with gold and red.
Bang! Bang! Bang!
Heavy collisions resounded, the earth roared—man and bird engaged in brutal combat.

……………………
On the coast, along the horizon, many cadets had gathered aboard the warship, all of them failed challengers.
Some lacked strength, others were paralyzed by fear, while the rest simply couldn’t hold on and chose to give up.
Of course, there were failures who would never return—for they had died, some leaving not even a corpse behind.
“This is only the first week, still far from half a month. So many have already come back—it seems Beast Island truly is a remarkable place.” Garp lounged on his chair, looking for all the world like a tourist.
“Perhaps, for them, it’s just too soon,” Zephyr replied expressionlessly.
“The rest is up to them.”
As time passed, more and more cadets were rescued, leaving fewer than twenty remaining.
And these twenty or so, without exception, would become future rear admirals and vice admirals.
Deep in the jungle,
Since his battle with the giant bird three days ago, Xuan Ye had grown far more cautious, for even after unleashing his powers, he had nearly died.
He still bore three savage claw marks across his chest; if not for the Devil Fruit’s extraordinary recovery, he would still be nursing his wounds.
Alert and resting atop a massive tree, Xuan Ye closed his eyes. Just earlier, he had fought a beast resembling a hybrid of giant elephant and mammoth, killing it only after a grueling struggle and sustaining many injuries.
“Ten days have already passed. Time is running short—I must seize the last five days for battle.” Taking a deep breath, Xuan Ye was struck by how quickly time had flown; in the blink of an eye, two-thirds of the fortnight had slipped away.
“Looks like I’ll have to go even deeper.”

………………
As for the temperature of the flames, there’s no need to quibble, for the author used comparisons based on the Thunder Fruit.