One Piece: Marine Luffy, Garp regrets it

Blood continued to seep from the corners of Yamato's mouth, her wolf-like features contorted in pain. It was evident she had suffered serious internal injuries from Kaido's devastating attack. Yet, wiping the crimson streak from her face, she seemed unconcerned with her wounds. Instead, her brow furrowed in deep concentration.

"This power..." she muttered, eyes narrowing as something stirred within her. "Is this the manifestation of Conqueror's Haki? I feel something resonating inside me."

Her voice grew more certain as understanding dawned. "It seems that as long as I channel it through my will, I can harness it..."

Hearing her instinctive musings, Kaido's expression froze momentarily in surprise before darkening further. A complex mixture of pride and frustration flashed across his imposing features.

That's right, he thought. It's this kind of raw talent that anyone could see with their naked eyes.

This child had awakened her Conqueror's Haki at the mere age of eight, and her strength had grown exponentially despite enduring the harshest conditions since childhood—hunger, isolation, and constant battles for survival within the Beast Pirates' fortress. Such exceptional potential was entirely befitting of Kaido's offspring, a fact that secretly filled him with satisfaction.

But unfortunately, this stubborn child had never aligned with his vision.

All Yamato ever did was scheme against him, dreaming of escape and freedom, completely wasting such magnificent potential! If only she could be more obedient. Even though she was a daughter rather than the son he'd initially wanted, Kaido would have gladly bestowed upon her the position of All-Star within the Beast Pirates, perhaps even his successor.

But fate had other plans. The more Kaido reflected on this reality, the more his anger intensified. The sight of his wayward daughter now standing against him, wearing a Marine coat no less, became increasingly intolerable.

Since you refuse to listen, he resolved grimly, then I no longer need such a daughter!

"Raimei Hakke: CONQUEST!" Kaido roared.

With terrifying speed that defied his massive size, Kaido launched forward. His kanabo, now coated in the dark crackling energy of advanced Conqueror's Haki, whistled through the air toward Yamato.

This attack carried no restraint whatsoever—Kaido was aiming directly for her head with killing intent.

Yamato sensed the deadly danger approaching. Her body instantly tensed, every hair standing on end as primal survival instincts kicked in. Without conscious thought, she twisted away from her original position with supernatural agility.

But Kaido's eyes flashed crimson as his advanced Observation Haki predicted her evasive path. With masterful precision, he altered his kanabo's trajectory from a downward smash to a sweeping arc that would still intercept her movement.

In the blink of an eye, Yamato found the massive weapon mere inches from her face. There was no room left to dodge. Gritting her teeth, she closed her eyes and braced herself to counter the devastating blow.

But in that crucial instant, a blur of movement intervened. A pair of elegant legs sheathed in the glossy black of Armament Haki appeared between them. The newcomer delivered a powerful kick directly to Kaido's wrist, momentarily disrupting his attack.

Seizing this precious opportunity, Yamato ducked beneath the kanabo's path. Together with her timely savior, she leapt backward, putting distance between themselves and the Emperor of the Sea.

Sweat beading on her forehead, Yamato first nodded gratefully to Hancock, who had arrived at the perfect moment.

"Thank you," she breathed, before turning her attention back to Kaido, eyes blazing with newfound understanding and rage.

"You bastard!" she shouted, voice trembling with emotion. "You truly intend to kill me, don't you?!"

Kaido massaged his kicked wrist, his gaze shifting between the two women now standing side by side. After hearing Yamato's accusation, he made no attempt to deny it.

"Yamato," he replied, his voice eerily calm and deliberate. "I'm done playing family with you."

The words fell heavy in the air between them. "Since you refuse to follow my path, you are of no use to the Beast Pirates or to me." His eyes narrowed dangerously. "What's more, you now wear the uniform of the Marines. You should understand better than anyone the blood-soaked history between Marines and pirates."

Listening to Kaido's cold declaration, Yamato tightened her grip on her kanabo until her knuckles turned white.

Whatever lingering hope she might have harbored—that somewhere deep inside this monster existed a father who cared for her—evaporated in that moment.

"I should have known long ago," she said, voice thick with emotion. "You are nothing but an inhuman monster. You always have been... and you always will be!"

Yamato's anguished roar echoed across the battlefield as memories of her childhood flooded back. She remembered a kind-hearted Beast Pirate who had secretly brought her food when Kaido had ordered her starved as punishment. The man, whose name she never even learned, had shown her simple kindnesses—smuggling meals, blankets, even a few moments of companionship to the lonely child.

But one day, Yamato discovered that this nameless pirate had been publicly executed on Kaido's orders. His crime? Showing compassion to the Emperor's unwanted daughter.

It wasn't just him. Almost everyone who had shown her kindness over the years had met a terrible fate. Those she might have called friends were either killed by Kaido or driven away by fear of his wrath, leaving her utterly alone.

Was it really Kozuki Oden she admired so deeply? Or was it what he represented—freedom to adventure, to forge meaningful bonds, to escape the cage her so-called father had constructed around her life?

And now, at last, she had succeeded. Standing alongside Luffy and his allies, she was finally living the life she had always dreamed of. She had made peace with her past and honored the memory of those who had suffered because of their connection to her.

"KAIDO!" The name tore from her throat like a battle cry.

With determined strides, Yamato advanced toward her father. The kanabo clutched in her hands began to respond to her heightened emotional state, vibrating subtly and emitting a low, resonant hum.

Hancock, who had initially moved to stop her reckless charge, froze in her tracks. Her eyes widened as she witnessed crimson and obsidian lightning suddenly crackling along the length of Yamato's weapon.

"That's—!" Hancock gasped in disbelief. "Advanced Conqueror's Haki?!"

Not only her, but Luffy and the others watching from a distance also witnessed this phenomenon. Astonishment spread across their faces as they realized Yamato had unlocked the ability to infuse her attacks with Conqueror's Haki—one of the rarest and most powerful techniques in the world.

Among the three in their makeshift family who possessed the King's disposition—Luffy, Hancock, and Yamato—she was the first to manifest this advanced application spontaneously in battle.

"This is getting interesting," Luffy remarked, his expression shifting to one of strategic assessment. He turned to the others nearby. "Koala, Gion, you two should join in now. Help Yamato hold her ground a while longer so she can acclimate to this new power."

Luffy had originally planned to let Yamato and Kaido exchange just a few blows—enough for her to vent her anger before they proceeded with their actual mission. But this unexpected development changed things. She needed time to familiarize herself with this newly awakened ability, and facing Kaido alone would be too dangerous while she was still learning to control it.

"W-what? I—I'm not ready yet!" Koala stammered, her face paling at the prospect of confronting the World's Strongest Creature.