Originally an African man from the Mediterranean, Briareos was used as a terrorist by the KGB while still a child. He sought political asylum in the former USA after killing the unit's commander of operations - for which he was put on the international "most wanted" list as an assassin. After meeting an agent from Special Security Forces, he began operating as a partner with the man's daughter, Deunan Knute. Caught in an explosion, the 31 year old survived only by undergoing a full cyborg body replacement - and has been making modifications ever since.
Briareos is a prime example of the technology of cybernetic implants in Appleseed. Although his body is almost completely artificial, he suffers little loss in humanity. His outer skin is elastic, capable of feeling sensation, and the temperature can be adjusted to the cyborg's preferences. He has eight eyes mounted on his head, four in his face (the large sensor in the middle is actually his nose) two at the bases of his "rabbit ear" sensors facing rearward, and two at the tips, which allow him to safely look around corners. His human brain is augmented by an auxiliary "brain" that acts as an information processor, and is capable of handling information in a conceptual format rather than hard numerical data. His cybernetics controller, the Hecatonchires system, is named after the same 100 handed giants from Greek mythology. It is capable of controlling dozens of limbs or other cyborg bodies independently from one another, with no additional strain on the user. In the manga, it is pointed out that a cyborg equipped with the Hecatonchires system is able to fully control an entire aircraft carrier on his own. This ability to process multiple limbs at once is seen in the film when he is seen using one rifle in his Landmate's arms, and another in the control arms.