Masked Deuce wears a mask over his face to conceal his true identity as he considers himself an adventurer more than a pirate.
Deuce is a man in search of adventure, disconnected from family ties, whose aim is to write a story. In his encounter with Ace he is annoyed to not be able to leave the island in which they are, but in time proved to be someone of liking for Ace. Although initially intended to kill him, due to lack of water and food, and believing the son of a criminal to understand that he was the son of the king of pirates, but subsequently feels guilty to see that Ace, after Several days, he did not hold a grudge.
Deuce was a medical student with bad grades. His parents were indifferent to him. He just wanted to have an adventure and did not want to be a wanted man. He had been eager to write an adventure essay like "Brag Men" (seen in Ohara). He was now incapable of escaping from a too beautiful desert island called "SIXIS" located in East Blue. The current around the island was pretty irregular that nobody can escape. He had come to the island in search of treasure claimed to be hidden there.
When he was talking to a skeleton next to him, he found that someone else had joined the conversation without realizing it. This is the first moment when "he" and Portgas D. Ace talked. Ace said politely, "Nice to meet you." The man thought Ace was about the same age as him. He considered Ace came to the island to rescue him, but Ace was also a victim due to his ship being wrecked. The man was annoyed that Ace was smiling cheerfully in spite of this predicaments. The man had spent three days on the island, whereas Ace six days. Ace said, "How about creating a raft with me?"
Ace kept asking the man about his name, but the man did not want to tell him about it since he had already thrown away his own name on the day he set out to ocean. Ace said, "We are already friends, right?" The man tried introducing his pen name as "Ace" borrowing Ace's name, but Ace objected and suggested him to make his pen name "Deuce" since he thought the pronunciations were similar. The man did not feel bad since the meaning of Deuce being "bad luck" fits into his current situation. Ace decided to call him "Masked Deuce" since the guy wore a mask so that Marines did not recognize his face.
Ace and Deuce talked about their family, and Ace mentioned Monkey D. Luffy in the talk with smile. Deuce happened to say, "If someone's father were Gol D. Roger, I'm sure he'd rather die." Ace suddenly became quiet and showed a very serious facial expression, which made Deuce realize that Ace is the real son of Pirate King. Deuce walked off with mixed feelings, telling Ace not to talk to him anymore.
Several days passed, Ace failed to escape from the island with his ship wrecked. "I can't die in such a place...!" He was not in a positive mood anymore. Deuce tried to find food and water, but in vain.
One day, Deuce found Ace grabbing a large fruit in his hand on a beach. Deuce was hungry and came to the conclusion that there is no problem even if he killed Ace since Ace is the son of a legendary criminal. Right before he attacked Ace with a tree branch, Deuce's stomach growled. Ace noticed him and considered that Deuce came to help him make a boat. Ace offered him to eat the fruit, but Deuce rejected it due to the feeling of guilty for trying to kill him.
Deuce finally realized that Ace was a nice person despite him being the son of Pirate King. As a result, they decided to share the fruit. Deuce felt it is the most terrible -but delicious at the same time- food that he had ever eaten. Deuce turned around and found Ace burning. Both of them were surprised at Ace's burning body. The fruit they ate was the Mera Mera no Mi.
After several days, Ace was capable of controlling his fire. Deuce called the ship "Striker" which moved forward by rotating plates with the help of fire. Deuce said it was a fake rumor that a treasure was hidden in the island. Ace answered with a smile, "Not sure." Ace reached his hand toward Deuce and said, "You'll come with me, right?" Deuce replied, "I can write a good adventure essay with you." They shook hands tightly. Ace declared, "I'm gonna go beyond Pirate King!" Thus, Spade Pirates were born.
- The name Deuce might be from a playing card with a rank of two, also a slang word for number two.
- Masked Deuce is the first character shown to eat a Devil Fruit but do not inherit it's powers.
- ↑ One Piece Manga and Anime — Vol. 57 Chapter 552 and Episode 461, The Spade Pirates are seen during Ace's fight with Jinbe.
- ↑ 2.0 2.1 ONE PIECE Magazine — Volume 1, Masked Deuce was introduced along with Portgas D. Ace's backstory.