The unnamed boy wears tattered clothing and a collar tied to A's ability. He has an X-shaped scar below his right eye.
Although not much is known about him, he started a conversation with Fyodor, mentioning how he is Ace's subordinate. He is also the one who witnessed Fyodor's plan in action, later being killed by him.
Before he was old enough to realize his surroundings, he was sold to a slave dealer and managed to end up in the Port Mafia. For the rest of his life, he was forced to wear a collar that was controlled by A's ability. Along with the rest of his comrade's, the boy wished to be freed from the collar and gain freedom. However, he believed defying and defeating A would be impossible. While talking to Fyodor, he mentions that it was his dream to one day become the boss of the Port Mafia, but soon says he was stupid to believe that his dream could become reality.
After Fyodor is hit with the wine bottle, the boy feels sympathy and tells him not to give up. He reveals his background about Ace, and the collars, and says it is impossible to defeat him. He is then startled by Fyodor's obvious blood lust, and intent to kill, but continues with his story. The boy then asks if he is not afraid, receiving no as an answer.
Later he is seen walking through the hallways, wondering if Fyodor has been killed by A, and that he never will be able to leave that cell. To his surprise, Fyodor is alive, and in search for the jewels. He continues to ask questions about A, and how he managed to escape. Fyodor tells him that A did not realize he was being manipulated, and that he purposely slipped the fake information about his ability to his kidnapper. The boy runs to back to the cell, only to find A hung by cords from a lamp. Fyodor then explains how he won the card game, and how he made A believe that he was in his consciousness, but never truly was. At a lost of words, the boy ask if he was after the Jewels, but his reply was also a no, and says that he was after a list of all the abilities of the Port Mafia members.
Fyodor explains that he cannot let anyone find out about what has happened, and announces he will grant the boy the 'great silence.' As he presses a finger to his forehead, the boy is killed in a single move. His final thoughts are that Fyodor will definitely destroy the mafia, and to be killed by such a guy is his way of dying, and it was not so bad of a life.
- Fandom dubbed him 'Topaz'. The real character has been given no official name.
- His nickname for Fyodor is 'Anemia Man'.