At the end of Adventure Time: Fionna and Cake (2023), Fionna makes a wish that restores color and life to the drained city and its people, including herself. Simon Petrikov confronts GOLBetty, reliving a pivotal moment in their past, and they part with mutual understanding. Betty returns to her fate as GOLB, while Simon, now free from the Ice King's crown, embraces his worth and purpose. Cake retains her powers and voice, choosing to remain as she is rather than return to normal. The story closes on a bittersweet note, with characters accepting their identities and destinies.

The finale unfolds with Fionna blowing leaves that carry her wish, gradually restoring color and vitality to the city's drained inhabitants. This act symbolizes renewal and hope, as the last speck of color reaches Fionna herself, signifying her reconnection to life and purpose. However, the Scarab, a mysterious entity, looms as a reminder of the fragile nature of their universe.

Simon Petrikov then faces GOLBetty, revisiting the moment when he stopped Betty from boarding a bus to Australia. This scene is charged with emotional weight, as they acknowledge the choices they made and the paths they took. Betty expresses no regrets, calling Simon her "everything," and Simon reciprocates with deep affection. Betty boards the bus, which transforms into GOLBetty, her destined form. Simon, now free from the Ice King's crown and in his own body, reflects on his past decision to become the Ice King out of despair, affirming his own worthiness of life alongside Fionna and Cake.

Meanwhile, Cake experiences a personal revelation. Having gained the ability to talk and stretch, she embraces her true self and decides not to revert to her previous cat-like state, which she views as a prison. This choice highlights her growth and acceptance of her new identity.

The final scenes show Fionna and Cake returning to a world that appears normal but carries the subtle changes wrought by their journey. They encounter friends like Marshall and Gary, who have also evolved, and Fionna shares the truth about their world existing within Simon Petrikov's mind. Cake's powers manifest openly, convincing others of their reality.

Each main character's fate is clear:

• Fionna regains her sense of self and purpose, accepting the complexities of her existence.
• Cake embraces her empowered form and newfound voice, choosing to remain as she is.
• Simon Petrikov is freed from the Ice King's curse, reconciles with Betty, and finds renewed meaning in life.
• Betty accepts her transformation into GOLBetty, fulfilling her sacrificial role.

The ending balances hope and melancholy, emphasizing themes of identity, choice, and acceptance without simplifying the characters' struggles or resolutions.

Yes, characters do die in Adventure Time: Fionna and Cake (2023). Notably:

• The Winter King dies when Fionna touches his crown to return it, causing the crown to lose its magic. Since the crown granted him immortality, losing it results in his death and the melting of his kingdom.

• BMO dies in a lifeless alternate reality after unsuccessfully trying to fix a broken remote.

• Several monsters (Fish Monster, Bear Monster, King Cockatrice) are killed by Finn Mertens and Jake the Dog during the series.

• Jake's death is implied but not explicitly shown or explained. The series is set in a future where Finn is older, and Jake is absent, suggesting he has died sometime before the events of Fionna and Cake. The showrunners have deliberately left Jake's death ambiguous, choosing not to depict how or when he died, as they consider it a downer and not central to the story. This ambiguity allows fans to speculate and preserves the character's legacy.

No other main characters' deaths are explicitly detailed in the series. The deaths that occur are mostly tied to plot points involving magical artifacts or battles with monsters.