Peter O'Toole, Olivier Gruner and Don Wilson all have their voices dubbed by other actors.
Bolo Yeung said to the director Salamat Mukhammed-Ali that he wants to devote his role in Diamond Cartel (2015) to his friend Bruce Lee . Lee fights Chuck Norris in his film The Way of the Dragon (1972) and a cat watches their battle. Bolo asked to bring a kitten and make the fight scene between him and Serik Bimurzin and the kitten is observer during the fight, same like in Bruce Lee's movie.
After Bolo Yeung joined the cast, the filmmakers created a new character in the story, especially for him.