Ryōtarō Okiayu is Zero's voice actor in the "Mega Man X" series ever since its fourth installment. He was grateful for the role he was given to do mostly in the crossover "Project X Zone". Lucas Gilbertson stated that he did not think of Zero as a robot but instead as a swordsman, making his work enjoyable. While finding it challenging, Gilbertson liked yelling during recordings, something that was common in Zero's character. Another aspect the actor enjoyed was the staff member he worked with and thus expected to voice Zero in the future.