Wikipedia
is the name given to the giant robots and monsters of The Big O anime series. Forty years prior to the events of the series, the world was turned into a vast desert wasteland and the survivors were left without memories. The megadeuses are portrayed as remnants of the previous civilization, a lost technology few citizens of Paradigm know how to control. The word is a blend of the Greek Megas, meaning "Great", and the Latin deus, meaning "god". The pilot of a "Big" megadeus is a , taken from Latin.
The robots were designed by series creator Keiichi Sato, who also designed the Mazinger mechas featured on the Mazinkaiser OVA and the mutant creatures of The SoulTaker TV series.
The designs are strange and "more macho than practical." Unlike the giants of other robot anime, the megadeuses do not exhibit ninja-like speed nor grace or possess voice-activated special attacks; but for what they lack in agility, they more than make-up in firepower and protection. The robots come armed with weaponry like missiles, piston powered punches, machine guns, and laser cannons.
The nature of the megadeuses is tied to the event forty years prior. In the final episode of the first season, Roger Smith has a flashback in the form of a nightmare: an army of "Big" megadeuses burn down the city as a group of bald children look on. In the second season premiere, he experiences a lucid dream of a town without domes, where its citizens have not forgotten who they are and megadeuses are nowhere to be found. In the final episode, he gets another burst of memories: the city stands in ruins and multiple "Big" megadeuses fight amongst themselves while a winged giant oversees the onslaught.
In the tradition of Japanese monster movies, The Big O features monsters modeled after conventional or mythological creatures. The series follows the " villain of the week" formula, meaning the protagonist is hired to do a job and by episode's end he must battle a monster using a giant robot of his own. Given the series' style, for some critics the robot battles seem out of place, while others praise the "over-the-top-ness" of their execution.
The term "megadeus" is officially used to refer to all giant robots and monsters seen in the series, though the term is often used to refer solely to the four "Big" robots. The "Bigs" are unique among the other megadeuses in that they are implied to be at least semi- sentient and have the ability to judge a person's worthiness to be a pilot through the phrase "Cast in the Name of God," then a declaration of either "Ye Not Guilty" or "Ye Guilty."