Series producer Keiji Inafune was not involved in the development of "Mega Man X6". He had originally intended for the fifth chapter in the series to be the last due to the death of Zero at that game's conclusion. "And so I’d always planned to make Zero come back to life in the Mega Man Zero series, but then "X6" comes out sooner from another division and Zero comes back to life in that, and I’m like, 'What's this!? Now my story for Zero doesn’t make sense! Zero's been brought back to life two times!'" Inafune also felt he owed fans of the series an apology for the decision to create "Mega Man X6", although the series was "starting to go in a direction out of control" at that point. Artist Haruki Suetsugu, who had worked on both previous PlayStation "Mega Man X" games, signed on as the game's primary character designer and promotional artwork illustrator. Suetsugu stated that the development schedule of "Mega Man X6" was tight. As such, he described his designs for the Maverick bosses were "relatively simple", and he took a similar approach to designing all of them: for instance, all of the Mavericks have the characteristic head fins and forehead jewel found on their creator Gate's helmet. The designs for other characters also feature unique traits, including Gate as a "merging of scientists and combatants, High Max as "big and strong", and the DNA-like Nightmare.