Gabriel Kaburaya

Gabriel Kaburaya is an American officer who is sent to the garrison in District 23 to eliminate the mafia influence. He serves as the primary antagonist of Season 3 and Last Season.

Background
Gabriel's parents were killed in a car accident when he was young. His younger sister narrowly survived the accident, however, the car that hit their parents was a mafia getaway car and Gabriel's sister was assassinated in the hospital in order to ensure silence. Since this incident, Gabriel has harbored an intense hatred of the mafia.

Season 3
Gabriel orchestrates "Operation: Great Justice," resulting in the death of Stella Maiougi, along with a hundred civilians. Shortly afterwards, he poisons and kills Yuuji Maiougi and successfully tricks Richard Maiougi into believing that the deaths are the work of the Golden Dragons. Richard attempts to assassinate Meijiu Lee and Tzulung Sun in revenge, however the assassination is botched by Yuki and Alan Aramaki. Their intervention results in Yuki's death.

Last Season
Gabriel watches as tensions brew between Primavera and the Golden Dragons.

Later, Richard appears at the American garrison, having been told the truth by Philip Butler. He attempts to kill Gabriel, leading to a shootout between the two. Richard is killed first. However, when Philip arrives and wraps his hand around Richard's, the gun in Richard's hand goes off, killing Gabriel.