Charlotte Brulee is the eighth daughter and nineteenth child of the Charlotte Family, making her a direct subordinate of the Emperor of the Sea, Big Mom, as an officer of the Big Mom Pirates. Her name is derived from the French dessert crème brûlée. As a major figure during the Whole Cake Island Arc, she is initially stationed in the Seducing Woods to ambush the Straw Hat crew as they attempt to retrieve Sanji. Her role in the story is complex; while she begins as a clear antagonist, she is repeatedly forced into the role of a reluctant ally after being captured, with her unique powers becoming a crucial asset for the Straw Hats and the Fire Tank Pirates in navigating the treacherous territory of Totto Land.

In terms of appearance, Brulee is designed to resemble a classic, stereotypical witch. She is a remarkably tall woman, standing approximately 350 centimeters, with a thin, almost hunched frame and long limbs. Her skin is a distinct grayish color. Her face is characterized by droopy yellow eyes with long lashes, a huge red hooked nose similar to her mother's, and a large mouth with purple lipstick. The most prominent feature on her face is a large, brown, diagonal scar that runs from right to left. This scar is a permanent reminder of a violent incident from her childhood. Her lavender hair is styled into several long, sharp, lock-like segments. She typically wears a frilly white dress decorated with roses, paired with a moss-green feathered sleeveless overcoat. This outfit leads characters like Carrot and Luffy to compare her appearance to a talking tree or a branch, much to her annoyance. When held captive, her captors force her into cleaner, more elegant attire.

Brulee's personality is a blend of pride, cruelty, deep-seated insecurity, and surprising tenderness. She is very prideful and confident in her own abilities, becoming deeply offended when underestimated by her family or confused with an inanimate object by her enemies. Due to the terrible scar on her face, she harbors an intense jealousy of people with beautiful, unblemished faces, to the point of expressing a sadistic desire to slice or burn them. She displays this cruelty explicitly when she threatens to boil Carrot alive. Despite her arrogance and a habit of underestimating her opponents, especially members of the Worst Generation, Brulee is also notably careless and clumsy, often finding herself easily captured or tricked. For instance, she is highly susceptible to tickle torture, which her captors use to extract information from her. Her cowardice surfaces clearly when she is in a helpless situation, becoming terrified of being branded a traitor by her own family, knowing it would mean death at the hands of her mother.

However, beneath this wicked exterior exists a genuinely caring and emotionally intelligent individual. She is deeply loyal to her family, weeping when the Whole Cake Chateau collapses with her siblings inside. This loyalty and care are most profoundly demonstrated in her relationship with her older brother, Katakuri. Their bond is one of the most significant in her life. When they were children, bullies who held a grudge against Katakuri slashed Brulee across the face, leaving her permanently disfigured. Despite the trauma, she did not blame her brother; instead, she comforted him, telling him it did not hurt and encouraging him to be himself. In response, the guilt-ridden Katakuri began covering his mouth and projecting an image of invincibility. Brulee has always known the truth about her brother's secret and the hardships he endured to protect the family, but out of deep respect and love, she never reveals it to anyone.

Her motivations are primarily rooted in family loyalty and survival. She shares her mother's dream of creating a utopia where every race lives together, though she hypocritically views Minks as mere animals. Her actions are driven by a desire to serve Big Mom and protect her siblings. However, when she is captured, her primary motivation shifts to self-preservation, as she lives in constant fear of being executed by her mother for perceived treachery. Her development throughout the arc is subtle but notable. She transitions from a boastful antagonist gleefully describing her brother Katakuri as undefeated to a horrified witness of his defeat. In the end, after being saved by Katakuri, she reveals her softer side, tending to his wounds after his legendary battle and acknowledging his pain, showing a depth of care that transcends the usual villainous archetype.

In combat and utility, Charlotte Brulee possesses significant and versatile abilities, primarily due to her having eaten the Mirror-Mirror Fruit, a Paramecia-type Devil Fruit. Her primary power is the creation and manipulation of mirrors. She can use these mirrors to reflect an opponent's attacks back at them. More strategically, she can trap individuals within an alternate dimension known as the Mirro-World. This world is a bizarre, checkerboard-patterned space that connects to every mirror in Totto Land, allowing those who navigate it to effectively teleport across the islands. After being captured, the Straw Hats force her to use this power to move around the archipelago undetected. Another formidable aspect of her fruit is the ability to transform herself, other people, and even animals into mirror images of someone else. These duplicates can perfectly mimic the appearance, voice, and even the Devil Fruit abilities of their target, as she demonstrates by creating a copy of Luffy with rubber powers. However, this transformation is purely visual when applied to animals, as their voices and physical capabilities do not change. Beyond her Devil Fruit, Brulee possesses notable physical strength, able to lift a person with one hand, and uses her long, sharp fingernails as weapons. She is also surprisingly agile and skilled in deceptive tactics like ambushes. For weaponry, she sometimes wields a large scythe.