One piece :I open the locks of the heart

Night had fallen on the Grey Terminal when I opened a dark portal, stepping through it to find myself once again where everything had begun. I immediately took to the air, silently gliding toward the noble house where I knew the keyhole of this island was hidden. My outfit—the one that had earned me the nickname "Spirit of the Shadows"—concealed every movement in the darkness.

As I approached the mansion, something new manifested before my eyes: hearts appeared above people without me needing to use Scan. Intrigued, I scanned my surroundings. A young maid, named Marie, had a pure white heart, while the woman she served, Ingrid, had a heart as black as the night itself. I wasn't surprised to see Ingrid whipping Marie with a riding crop, her cruel gaze betraying a sadistic pleasure.

I slipped discreetly into the house, observing the servants. Most of them had white or blue hearts, symbols of goodness or neutrality. Yet, despite my observations, I had not seen anyone with a golden yellow heart like Luffy's. Even mine was just white, simple and silent.

After a bit of recon, I finally found the keyhole in the basement, where the master of the house was indulging in a disgusting act with a chained-up slave. The sight filled me with instant disgust. Without wasting time, I approached the man and knocked him out with a swift blow. He collapsed, unconscious, and I hurried to free the woman, covering her bruised body with a sheet.

I then moved toward the keyhole, invisible to everyone but me, and raised my Keyblade. A flash of dark energy shot from the tip of the blade, entering the keyhole. Immediately, a torrent of shadows spilled into the room, far more impressive than what I had seen on the small island before. Thousands of small dark creatures with blue eyes emerged from the keyhole, quickly dispersing throughout the mansion.

I then saw three shadows leap upon the unconscious master of the house. In an instant, they transformed him into a Sans-cœur: a mere Soldat, who promptly took his place by my side. However, I noticed that I didn't gain any physical reinforcement if the conversion was done by these shadows instead of by me.

"That's unfortunate..." I murmured to myself. "I should just unlock an island's keyhole after dealing with the big fish myself."

Carrying the now-unconscious woman in my arms, I headed upstairs. There, I was greeted by a scene of chaos: the household servants surrounded Ingrid, screaming in panic as they watched the shadows patrolling the room. The dark creatures paid them no mind, focusing only on Ingrid, their primary target.

"What... what are these things?!" one of the servants cried, trembling with fear. "They're coming for us!"

"They're going to devour us!" screamed a maid, cowering behind a piece of furniture, her terrified gaze fixed on the Shadows moving silently through the room.

Ingrid, still as arrogant as ever despite the situation, stood in the center of the room, her black heart beating at an unnerving pace. She lifted her chin and, in an authoritarian tone, addressed her servants, her eyes burning with rage. "Protect me, you idiots! Defend me! I am your mistress! I order you to defend me, even if it means dying for me!" she screamed with unsettling ferocity.

But her words had the opposite effect. Fear was etched on the servants' faces, and none of them moved to help her. They were frozen, paralyzed by the terror that gripped them.

I let out a sigh, observing the scene with disinterest. "Ridiculous," I murmured before raising my hand. "Rondouillard, go."

Immediately, a Rondouillard emerged from my shadow and charged into the fray, scattering the panicked servants like leaves in the wind. Ingrid let out a piercing scream, realizing that no one would come to save her. The Shadows took advantage of the distraction and pounced on her. In an instant, the horrible woman was transformed into a Sans-cœur, an Opéra jaune. The small, now harmless creature quickly fled into my shadow, joining my growing army.

Silence fell over the room, and the servants simply stood there, dazed, watching as the Shadows now calmly patrolled the mansion. None of them were harmed, and the Shadows showed no signs of aggression toward them anymore.

I turned my head toward Marie, the young maid I had seen earlier. She was terrified but stood tall, her fists clenched.

"You," I said, pointing at Marie. "Come help this woman." I indicated the unconscious servant I had carried in my arms. "Know that this island will now be protected from crime... by them." I gestured to the small blue-eyed creatures now patrolling peacefully, with no hostility whatsoever.

Marie, visibly surprised by my order, hesitated but approached despite her fear.

I gently laid the unconscious woman down before straightening up. Then, without another word, I rose into the air, my dark garments trailing behind me like the tatters of a specter. The servants' eyes followed me, and I knew that, for them, I was now more than just a legend. I had become a real ghost, a silent shadow watching over this island.

From the sky, I watched the spectacle unfold beneath me. The Sans-cœur spread like a dark wave through the city, moving silently, hunting those whose hearts were stained black, gray, or red. These hearts appeared above certain people like beacons in the night, signals the creatures couldn't ignore. Chaos quickly ensued, with panicked screams echoing through the air like a symphony of terror.

The once quiet alleyways were now overrun with Shadows and Soldat Sans-cœur. Everywhere, people were running, desperately trying to escape the creatures chasing them. The corrupt nobles and criminals of the city, recognizable by their dark hearts, were trapped, their cries of distress filling the air.

"Help!" screamed a woman dressed in a luxurious gown, stumbling over the cobblestones as a group of Soldat Sans-cœur lunged at her. Her figure disappeared under a wave of shadows, her corrupted heart torn from her chest before she herself transformed into a creature of darkness.

I floated above the city, invisible to all. The Sans-cœur focused on the targets below, completely ignoring me. As I slowly made my way through the streets, I observed the transformations multiplying. I couldn't claim the Sans-cœur that emerged directly from the keyholes, but those that resulted from transformations belonged to me. Each time a person with a black or red heart was overwhelmed, I discreetly added the resulting Sans-cœur to my growing army.

The screams of terror multiplied, rising above the rooftops. Men and women tried to barricade themselves inside their homes, but the Shadows slipped under doors and through windows. Some nobles, who had believed their rank would protect them from any danger, now found themselves trapped, screaming for help as their bodyguards were swiftly overwhelmed.

However, not all the kingdom's guards were powerless. Unlike the household servants I had seen earlier, these soldiers were competent. They fought valiantly, their swords and spears gleaming in the torchlight. Every strike against a Shadow temporarily dissipated it, and the Soldat Sans-cœur were pushed back by effective tactics.

"Hold the line!" shouted an officer, his heart oddly gray, faintly floating above him. He struck down a Shadow with the back of his sword, dispersing it into a cloud of darkness. "Don't let these creatures reach the city center!"

But despite their bravery, the soldiers began to find themselves overwhelmed. For every Sans-cœur they repelled, several more appeared, slipping into the alleyways or emerging from the shadows cast by the torches. The soldiers' cries started to blend with those of the civilians, and gradually, chaos took over.

"There are too many of them!" cried one of the soldiers, struggling to maintain his position as a Soldat Sans-cœur struck him in the chest. He staggered back, but his pure blue heart protected him. Unlike the officers with their gray hearts, most of the soldiers remained unscathed. They only sustained superficial injuries, but it did nothing to change the inevitable tide of shadows crashing down upon them.

Eventually, the captain of the guards, a man whose face bore the marks of years of service, raised his hand in a decisive gesture. His expression hardened as he watched his men being pushed back, and he made a decision.

"Retreat! Immediate retreat!" he ordered, his voice echoing through the crowded streets. "Abandon the lower city; we must protect the king and the palace!"

The soldiers exchanged glances, some hesitating for a moment. Abandoning the lower city meant leaving the lesser nobles and corrupt citizens to fend for themselves. But they had no choice. The Sans-cœur were too numerous, and their primary mission was clear: protect the royal family at all costs.

"Don't dawdle, to the palace, now!" yelled another officer, his gray heart almost invisible under the onslaught of creatures.

The guards began to withdraw methodically, forming tight ranks while covering their retreat. The desperate cries of the nobles left behind echoed into the night, but no soldier turned back to help them. They knew their duty lay elsewhere.

I continued to float above, calmly observing the soldiers' retreat. It was ironic to see these corrupt nobles, used to being protected by their power and wealth, now left at the mercy of the Shadows they had attracted themselves. For them, there would be no mercy, and they would be transformed into Sans-cœur, joining my endless army.

Once the soldiers were gone, a smile spread across my face. "Chaos is taking its course," I murmured, as I claimed another newly born Sans-cœur from a fleeing man. The Shadows, now without resistance, patrolled peacefully, tracking down the remaining targets.

The corrupt nobles of this city had met their end. Now, the city belonged to the shadows, and soon, it would be under my protection.

The once-quiet alleyways are now overrun by Shadows and Soldat Sans-cœur. Everywhere, people are running, desperately trying to escape the creatures chasing them. The corrupt nobles and criminals of the city, recognizable by their dark hearts, are trapped, their cries of distress filling the air.

"Help!" screams a woman dressed in a luxurious gown, stumbling on the cobblestones as a group of Soldat Sans-cœur lunges at her. Her figure disappears beneath a wave of shadows, her corrupted heart torn from her chest before she transforms into a creature of darkness herself.

I float above the city, invisible to all. The Sans-cœur focus on the targets below, completely ignoring me. As I slowly move through the streets, I observe the transformations multiplying. I can't claim the Sans-cœur that emerge directly from the keyholes, but those resulting from transformations belong to me. Every time a person with a black or red heart is overwhelmed, I discreetly add the resulting Sans-cœur to my growing army.

The screams of terror multiply, rising above the rooftops. Men and women attempt to barricade themselves in their homes, but the Shadows slip under doors and through windows. Some nobles, who believed their rank would protect them from danger, now find themselves trapped, screaming for help as their bodyguards are swiftly overwhelmed.

However, the kingdom's guards are not all powerless. Unlike the household servants I saw earlier, these soldiers are skilled. They fight valiantly, their swords and spears gleaming under the torchlight. Every strike against a Shadow temporarily disperses it, and the Soldat Sans-cœur are pushed back by effective tactics.

"Hold the line!" shouts an officer, his heart oddly gray, faintly floating above him. He strikes down a Shadow with the back of his sword, dispersing it into a cloud of darkness. "Don't let these creatures reach the city center!"

But despite their bravery, the soldiers begin to get overwhelmed. For every Sans-cœur they repel, several more appear, slipping into the alleyways or emerging from the shadows cast by the torches. The soldiers' cries start to blend with those of the civilians, and gradually, chaos takes over.

"There are too many of them!" cries one of the soldiers, struggling to hold his position as a Soldat Sans-cœur strikes him in the chest. He staggers back, but his pure blue heart protects him. Unlike the officers with their gray hearts, most of the soldiers remain intact. They only suffer superficial injuries, but it doesn't change the inevitable tide of shadows crashing down upon them.

Finally, the captain of the guards, a man whose face bears the marks of years of service, raises his hand in a decisive gesture. His expression hardens as he watches his men get pushed back, and he makes a decision.

"Retreat! Immediate retreat!" he orders, his voice echoing through the crowded streets. "Abandon the lower city; we must protect the king and the palace!"

The soldiers exchange glances, some hesitating for a moment. Abandoning the lower city means leaving the lesser nobles and corrupt citizens to their fate. But they have no choice. The Sans-cœur are too numerous, and their primary mission is clear: protect the royal family at all costs.

"Don't dawdle, to the palace, now!" yells another officer, his gray heart almost invisible under the onslaught of creatures.

The guards begin to withdraw methodically, forming tight ranks while covering their retreat. The desperate cries of the nobles left behind rise into the night, but no soldier turns back to help them. They know their duty lies elsewhere.

I continue to float above, calmly observing the soldiers' retreat. It's ironic to see these corrupt nobles, used to being protected by their power and wealth, now left at the mercy of the Shadows they themselves attracted. For them, there will be no mercy, and they will be transformed into Sans-cœur, joining my endless army.

Once the soldiers are gone, a smile spreads across my face. "Chaos is taking its course," I murmur, as I claim another newly-born Sans-cœur from a fleeing man. The Shadows, now without resistance, patrol peacefully, hunting down the remaining targets.

The corrupt nobles of this city have met their end. Now, the city belongs to the shadows, and soon, it will be under my protection.

This kingdom was truly rotting with corruption. As I hovered over the city, watching the Sans-cœur spread, a chilling realization struck me: out of the 20,000 inhabitants of this city, nearly 5,000 had already become Sans-cœur. Most of them were Shadows and Soldats, the most common creatures, but I had also witnessed a few surprises. Among this dark tide, I had spotted three Soldat Volants, two Rhapsodies Bleues, and a Requiem Vert.

I floated silently, contemplating these transformations. It was both fascinating and troubling. These special creatures, these rare Sans-cœur… Why weren't there more of them, considering how many corrupted hearts had been changed? A theory began to form in my mind.

The rarity of these special Sans-cœur must be linked to the inner strength of the individuals being transformed, I thought as I watched them spread across the city. The Shadows, which seemed to appear in large numbers, probably came from those whose hearts were weak, with little will or conviction. These people were just lost souls, consumed by darkness without a fight.

But these Soldat Volants and Rhapsodies… they must be different. I started to understand that the stronger a person was, the more their Sans-cœur could take on a specific, powerful form. The Soldat Volants, with their agility and ability to move through the air, likely came from individuals with some skill or authority. Perhaps former skilled guards, nobles with strong wills, but still corrupt nonetheless.

The Rhapsodies Bleues, with their control over the elements, and the Requiem Vert, capable of healing, were even rarer. These creatures had to come from people with particular talents, perhaps musicians, healers, or individuals with a deeper connection to elemental energies. Such transformations were not random.

The link between a person's inner strength and the form of their Sans-cœur seems undeniable, I continued to think, scanning the surroundings. This explained why most of the Sans-cœur were Shadows: most people, even corrupt ones, didn't have the strength to become anything more than a simple Shadow in the army of darkness. Only a few had enough strength or skill to transform into more formidable creatures.

I let a slight smile form on my face. It's almost like a natural selection of sorts. Those who held power in life were transformed into more dangerous, specialized creatures. But in the end, they all joined my army, whether as Shadows or as special Soldats.

This theory about the transformation of the Sans-cœur also explained why I hadn't yet seen any particularly powerful Sans-cœur born from these corrupted masses. To create something like that, it would require someone with extraordinary strength of character or power, far beyond these corrupt nobles or lowly criminals.

I let my gaze sweep over the city. 5,000 Sans-cœur, and this is only the beginning, I thought, satisfied with my discoveries. The strength of my troops was growing, and I now understood that there was even greater potential to explore if I could transform the right individuals.

The rare creatures I had acquired, though few in number, would prove to be valuable allies. Their rarity only increased their worth in my army.

"It's decided. I'll keep an eye on those who show a strong heart, even if it's corrupted. They could become valuable assets in the battles to come, especially with my journey ahead. East Blue has a few individuals who might confirm my theory," I murmured before disappearing into the air, my mind focused on the future.

(Author's note: I'm writing here to clarify that the color of a heart will entirely reflect my interpretation of the person, taking into account various factors. For example, the bandits of Dadan who raised Luffy—I don't classify them as evil because in the original work, I don't recall them committing atrocities, and their overall behavior is good. Therefore, their hearts are blue for everyone, and gold for Dadan due to her involvement with the two rascals and her reaction to Ace's death.) I hope you enjoy this work! ^^