Cassandra made her decision early. The Marines? Not a chance. She had no interest in their justice, their rules, or their hierarchy. What she wanted was freedom to chase strength, to collect the world's greatest swords, and to carve her name into history.
She kept her name Cassandra. It was a name that carried her past life, her purpose and her ambition.
Her training was merciless. If Zoro's regimen was extreme, hers was monstrous. She pushed her body to its absolute limits, always looking for a new breaking point, then shattering it.
She incorporated every training method she had seen in anime. From weight training and endurance drills to speed-focused exercises and advanced swordsmanship routines, she practiced them all. She quickly realized that techniques like the breathing styles from Demon Slayer and other „ordinary" skills were useless, because this world followed different rules. Strength came from physical effort, battle experience and, strangely enough, sheer food intake. To master the art of overeating and using the energy to strengthen her body and restoring her stamina was essential.
Morning Routine: A 20-kilometer run with weights strapped to her body, followed by a thousand sword swings using progressively heavier weights.
Midday Training: Strength drills, lifting boulders, performing one-finger push-ups, balancing on a tree log while swinging her sword. She even copied Saitama's infamous workout and doubled it.
Afternoon Combat Training: Sparring against multiple opponents (friends of her dead parents), dodging thrown projectiles while „blindfolded" (she only took of her glasses of) to start her haki training and practicing quick-draw techniques. She trained barefoot on hot sand and slippery ground, forcing herself to adapt to any terrain.
Evening Refinement: Silent movement drills, practicing drawing and cutting in total darkness and meditative techniques to learn about sword intent.
Meditation became a core part of her training. She focused on the soul of the blade, trying to understand the legendary ability to cut even steel. She knew from Zoro's journey that swords had personalities and only those who understood them could reach the peak of swordsmanship.
To cut steel was not her only goal. Cassandra wanted to master the use of the so called sword intent. Every object in the world, including swords and the air itself, carries its own "will" and a true swordsman learns to attune themselves to this will through rigorous meditation and training.
Long hours of meditative discipline allow Cassandra to sense the soul of things, an extension of what Zoro uses to "hear" the breath of steel.
Sword intent allows the user to manifest their emotions, beliefs and when mastered properly leads to the use of elemental powers into their strikes. Kin'emon's "Fire Cutting" is believed to be an expression of his internal burning conviction, creating fire without a Devil Fruit. Brook's "Chill of the Underworld" comes from his soul: It is literally his Devil Fruit-enhanced spiritual energy manifesting in sword strikes.
Wind seemed like a good start. She would slice through falling leaves without touching the branches they fell from. With each swing of Shigure, she trained herself to feel the air bend to her intent. Eventually, her slashes moved with such speed and precision that they created gusts with thin arcs of cutting pressure that split logs from meters away.
She created her own version of the legendary flying slash. She named it the Kaze no Ikari (Wrath of the Wind).
A flying slash so fast and sharp it sounds like a jet flying through the air, capable of cleaving foes from across the battlefield.
Fire was by far her favourite element. The raw power to burn everything in your path is exillering. To understand it, Cassandra lit fires around her training ground and fought beside them, allowing their heat to press against her skin. She trained until her body ignored the pain. She channeled her rage, the picture of the damn thief before her eyes, the foolishness of the weak people only awaiting slaughter and poured it into her blade.
One night, a spark leapt from the edge of Shigure, as she struck a training dummy. She didn't stop. She struck again. This time, the blade hissed and the dummy ignited.
Cassandra created a slash engulfed in fire and called it Hono no Hishō-zan (Soaring Flame Slash).
An attack infused with burning conviction, it scorches whatever it touches and leaves a trail of fire in its wake.
While Wind was freedom and Fire was fury, Ice was detachment. Cassandra submerged herself in cold water until she could control her breathing. She trained at dawn, when the grass was slick with frost, mimicking the delicate structure of ice with her footwork and the razor-thin edge of her blade.
She stopped seeing ice as "cold" and started seeing it as perfect focus. It is sharp and merciless.
Cassandra called the attack Yuki no Setsudan (Snow's Severing Edge).
A silent, graceful strike that freezes people upon contact completly, paralyzing limbs or sealing arteries with pinpoint control.
Lightning couldn't be tamed. It could only be channeled and was the hardest endevour for her.
Cassandra stood in the rain, sword held high, waiting for the storm. When it finally came, she meditated in the heart of it, letting the tremors of thunder beat against her chest and the flashes of light burn behind her eyelids. She visualized her energy, her will, racing through her body at impossible speeds.
She practiced speed slashes until her arms bled, pushing her reactions beyond normal limits. Eventually, she felt it that snap, like the ignition of voltage in her muscles.
This time she wanted to learn a technique from another anime. Raikiri (Lightning Cutter) from Chivalry of a failed Knight was a charged, ultra-fast stab or slash surrounded by violet electricity used by Tōka Tōdō. It will be her ultimate move for the time beeing.
Over the years her body adapted, growing stronger each day. At eighteen she stood 190 cm tall. Her midriff showed the first signs of a six-pack. Her arms looked strong, but not overly muscled and her breasts were large and full typical for the world of One Piece, giving her an intimidating yet undeniably attractive physique.
Cassandra also styled her beautiful blue hair in a high ponytail like tashigi had in the later parts of the anime, but her hair was a bit longer.
The only flaw was her ridiculous bad eyesight without her red glasses. To be safe, she always had three spares ready.
She looked in the mirror one morning and smirked.
"This… this is my dream body."
Life in the world of One Piece was strange. Cassandra had always admired well-proportioned, beautiful women and in this world, there were plenty. Everywhere she went, she saw women with perfect figures, their bodies looking like works of art sculpted by the gods. From warriors to noblewomen, from bounty hunters to pirates, the female body in this world was a blessing to behold. Thank you Oda-sensei.
But there were also abominations. Men with torso-sized heads, tiny legs and massive arms, or giant round bellies but shredded abs. The sheer variety of body shapes was something she could never have imagined in her past life. It took some time to get used to this. Damn you Oda.
"One Piece logic is wild."
Still she had her goals and ogling beautiful women, was only a secondary pleasure. Her true passion lay in swords.
And soon, she would claim another.
One day, her path led her to an infamous target: Billy the Orca Killer, captain of the Yes Pirates.
A hulking brute, Billy stood well over three meters tall. His body is a mountain of muscle and scars. He was famous for his cruelty, having slaughtered entire villages for sport. In his hands was a blade worthy of legend Yamaoroshi, one of the Fifty Skillful Grade Swords.
The katana was a masterpiece. Its green, shimmering blade gleamed under the sunlight, reflecting an almost ethereal glow. The crossguard was simple but elegant, a design befitting a weapon of this caliber. Cassandra knew the moment she saw it, this was a sword meant for her.
She found Billy in a lawless town, surrounded by his crew. Thirty men that are all armed and all very confident.
"Poor fools."
Billy sneered. "You? You're that so-called 'Dancing Blademaster' everybody is talking about lately? Girl, you got guts, I'll give you that, but do you really think you can take me on?"
Cassandra was a bit puzzled. "I am still far away from beeing a blademaster, but for weak idiots like you I probably look like the grim reaper."
The insult worked. With a roar, Billy ordered his men to attack.
They never stood a chance.
Cassandra vanished. One second she was there, the next she was gone. Then came the storm of steel.
One step, one strike and two bodies fell. A twist, a counter and five more goons collapsed in a spray of crimson. A spinning slash, three, four, five strikes and all were cut down before they even knew what happened.
Within seconds, Billy was alone. His entire crew lay in pieces at Cassandra's feet. These small fries only existed to get chopped into pieces by her blade.
He snarled, gripping Yamaoroshi. "Damn bitch! You think you're strong just 'cause you're fast? I'll crush you!"
He charged, his monstrous strength bringing down Yamaoroshi in a devastating arc. The ground split apart where his blade landed. If it had connected, it would have been fatal.
But Cassandra was already behind him.
"Too slow."
Billy turned, swinging wildly, but she weaved through his attacks with ease. His strikes were powerful but reckless, while hers were precise and deadly. She struck, opening wounds. Her skills were way beyond someone from East Blue. Billys fate was death by a thousand cuts.
Desperation flashed in his eyes. He roared, putting everything into a final, full-force downward slash.
Cassandra met him head-on.
Her blade clashed against Yamaoroshi and for a moment, time seemed to stop.
Then Cassandra seemed to vanish appearing behind Billy.
Billy's eyes widened in shock before his body split in half, collapsing lifelessly onto the ground.
She flicked the blood off her blade and turned to Yamaoroshi.
It was… perfect.
A beautiful green-bladed katana, its shimmering surface unmarred by battle. But something was happening. As she picked it up, the blade shrunk, adapting to fit her size perfectly.
"A sword acknowledges and chooses its wielder, huh?"
With a smirk, she lifted her prize.
Yamaoroshi was hers now.
The very first sword she claimed all by herself for her ever-growing collection in this world.
And her legend was just beginning.