The episode begins with a flashback to the past, showcasing Kyros, the legendary warrior of Dressrosa, who is seen fighting valiantly in the Colosseum. He is depicted as a fierce and honorable fighter, admired by the people of Dressrosa. The scene transitions to the present, where Kyros, now a toy soldier, is regaining his human form after the defeat of Sugar, the Devil Fruit user who turned him into a toy. As he transforms back, he is filled with a mix of emotions, including determination and a sense of urgency to protect his daughter, Rebecca.

Kyros stands tall, now fully human again, and is overwhelmed with joy and relief at being reunited with his true self. He quickly realizes the gravity of the situation in Dressrosa, where Doflamingo's tyranny still looms. He vows to fight back against the oppression that has plagued his homeland. The scene shifts to the ongoing battle in the Colosseum, where Luffy and the other gladiators are preparing to confront Doflamingo's forces.

Meanwhile, Doflamingo is shown in his palace, confident and smug, as he discusses his plans with his subordinates. He underestimates the resolve of the gladiators and the citizens of Dressrosa, believing that his power is unassailable. The tension builds as Kyros, now fully aware of his capabilities, decides to take action. He charges into the fray, ready to confront the enemies that threaten his daughter and his homeland.

As Kyros enters the battlefield, he is met with a wave of enemies. He showcases his incredible swordsmanship and combat skills, cutting through the foes with precision and strength. The animation highlights his fluid movements and the intensity of the fight, emphasizing his determination to protect those he loves. The citizens of Dressrosa watch in awe as the legendary warrior they thought was lost returns to fight for them.

The scene shifts back to Luffy and the gladiators, who are also engaged in their own battles against Doflamingo's forces. They are inspired by Kyros's return and rally together, pushing forward with renewed vigor. The camaraderie among the fighters is palpable, as they each draw strength from Kyros's legendary status and their shared goal of liberating Dressrosa.

Kyros continues his all-out attack, taking down multiple enemies with a combination of powerful strikes and strategic maneuvers. His internal motivation is clear; he fights not just for himself, but for Rebecca and the future of Dressrosa. The animation captures the emotional weight of his actions, showing flashbacks of his past and the sacrifices he made for his family.

As the battle rages on, Doflamingo becomes aware of Kyros's resurgence and grows increasingly agitated. He orders his subordinates to focus on eliminating Kyros, seeing him as a significant threat to his reign. The tension escalates as Kyros faces off against some of Doflamingo's strongest fighters, showcasing his resilience and tactical prowess.

In a climactic moment, Kyros confronts one of Doflamingo's top lieutenants. The fight is intense, with both combatants exchanging powerful blows. Kyros's determination shines through as he recalls his love for Rebecca and the hope of a free Dressrosa. He channels this emotion into his fighting, ultimately gaining the upper hand and defeating his opponent.

The episode concludes with Kyros standing victorious, surrounded by the remnants of the battle. The citizens of Dressrosa cheer for him, their spirits lifted by his bravery and strength. Kyros, still focused on his mission, looks towards the palace where Doflamingo resides, ready to continue the fight for his daughter and the future of their home. The scene fades out, leaving viewers with a sense of anticipation for the next steps in the battle against Doflamingo's tyranny.

In episode 677, Kyros is driven by a deep desire to protect his daughter, Rebecca, and to reclaim his honor as a warrior. After being turned into a toy and losing years of his life, he is determined to confront Doflamingo and free Dressrosa from his tyranny. His emotional state is fueled by a mix of anger, regret, and a fierce protective instinct.

Kyros' fighting style in this episode showcases his strength and agility, honed over years of battling as a gladiator. His movements are fluid and powerful, reflecting his determination and the weight of his past. As he fights, he channels his pent-up frustration and sorrow into each strike, symbolizing his reclaiming of identity and purpose.

During Kyros' all-out attack, Rebecca serves as both a source of motivation and emotional support for Kyros. She watches from the sidelines, filled with hope and pride as her father fights. Her presence inspires Kyros to push beyond his limits, and her belief in him reinforces his resolve to protect her and their home.

The episode vividly illustrates the suffering and despair experienced by the citizens of Dressrosa under Doflamingo's rule. Flashbacks and scenes of the townspeople's reactions to Kyros' return highlight their longing for freedom and justice. The atmosphere is tense, filled with a mix of fear and hope as they witness Kyros' determination to fight back.

Key moments that signify Kyros' transformation include his initial struggle to regain his strength and the emotional flashbacks that reveal his past as a proud warrior. As he recalls his memories and the love for his daughter, he gradually sheds the remnants of his toy form, culminating in a powerful display of his fighting spirit as he confronts Doflamingo, symbolizing his full return to form.

In "One Piece" Season 16, Episode 677, titled "The Legend is Back! Kyros' All-Out Attack!", there are several elements that may be considered objectionable or upsetting for children or sensitive viewers:

1. Violence: The episode features intense battles and combat scenes, including characters engaging in physical confrontations that may be graphic in nature. The depiction of injuries and fighting can be intense.

2. Emotional Struggles: Characters experience significant emotional turmoil, including themes of loss, betrayal, and the struggle for freedom. These emotional scenes may be heavy for younger viewers.

3. Dark Themes: The episode touches on themes of oppression and suffering, as characters confront their past traumas and the harsh realities of their situations.

4. Character Transformations: Some characters undergo dramatic transformations that may be frightening or unsettling, particularly for younger audiences.

5. Mature Situations: There are moments that imply darker aspects of human nature, such as manipulation and revenge, which may not be suitable for all children.

While "One Piece" is generally aimed at a younger audience, these elements may require parental guidance for sensitive viewers.