Doctor Ciel (シエル Shieru) is a supporting protagonist and the main heroine of the Mega Man Zero series. A human scientist, Ciel sought out the legendary Reploid hero, Zero, to fight back against the tyranny of Neo Arcadia. Ciel leads the Resistance to support Zero. In the Mega Man ZX series, Ciel is the creator of the main six Biometals and is the founder of the Guardians, though she never appears outside of flashbacks. As of Mega Man ZX Advent, her status is unknown.