TV Special
Description
Myskina Acier is a scientist and the widowed father of Myskina Olga, introduced in the One Piece television special Heart of Gold. Two hundred years before the events of the story, he lived on the lost island of Alchemi with his wife and young daughter. When his daughter Olga fell fatally ill with the incurable South Blue Emperor Fever, Acier dedicated himself to creating a miraculous substance known as Pure Gold. His invention succeeded in halting Olga's aging and curing her disease, but the treasure attracted greedy outsiders who attacked the island. During the raid, his wife was killed. Blaming her father for the tragedy, Olga threw the Pure Gold ring into the sea, which awakened a gigantic anglerfish called Bonbori. The creature swallowed the entire island, along with Acier and Olga, separating them.

Inside Bonbori's stomach, Acier survived for two centuries. He assumed Olga had died, and to avoid being eaten by the dinosaurs that lived in the creature's gut, he disguised himself in a homemade dinosaur costume. His diet consisted almost entirely of meat, which caused him to become overweight. Over time, he learned to communicate with the dinosaurs and with water‑strider lizards, developing a peculiar talent for making them laugh with a comical facial expression. Despite his unkempt appearance and eccentric behavior, Acier remained a brilliant scientist and an accomplished architect. He had designed the complex maze of traps and puzzles that protected the old mine where his laboratory and the remaining Pure Gold were stored.

Acier's core motivation has always been the well‑being of his family. He created the Pure Gold without regret, even though it indirectly led to his wife's death, because it saved his daughter's life. When the Straw Hat captain Monkey D. Luffy meets him inside Bonbori and reveals that Olga is still alive, Acier breaks down in joyful tears. He immediately agrees to help Luffy rescue her and the other Straw Hats. Throughout the adventure, Acier acts as a guide through the inner landscape of Bonbori, using his knowledge of the local creatures and his ability to tame a water‑strider lizard he names Chavez. His role is both that of a tragic figure seeking redemption and a comic relief character, as his dinosaur costume and silly face provide levity.

In the final confrontation with the treasure hunter Mad Treasure, Acier reunites with his daughter. He proves willing to sacrifice himself to save her, but the Straw Hats ultimately prevail. After escaping Bonbori's stomach, Acier and Olga are reconciled, and he expresses a desire to spend the rest of his life peacefully with her. In the epilogue, he creates a serum that restores his youthful appearance, though the timeline of that event is shown only in the closing credits.

Notable for his ingenuity and his unwavering love for his daughter, Myskina Acier is a sympathetic scientist whose invention brought both salvation and tragedy. His key relationships include his daughter Olga, whom he adores and from whom he was estranged; Luffy, who rekindles his hope; and the various animals of Bonbori's gut, with whom he forms unlikely bonds. His development tracks from a guilt‑ridden, isolated hermit to a hopeful father ready to embrace the future. His abilities are scientific (chemistry, architecture), survival‑based (animal communication, disguise), and comedic (his expressive face), but he has no notable physical strength in combat.