Technology & Combat Characteristics
A second generation GAT-X machine, the GAT-X252 Forbidden Gundam was designed for infiltrating and raiding enemy bases and to fulfil this role, it can transform into a "High-Speed Assault Form" by flipping its huge backpack unit over its head. Like the other two second generation units, the Forbidden is equipped with Trans-Phase armor (TP armor). Its armaments consists of head-mounted CIWS, forearm-mounted machine guns, a handheld scythe and backpack-mounted railguns and plasma cannon, both of which are usable only in "High-Speed Assault Form".
As indicated by its model code, the Forbidden utilized a X200-series frame like the GAT-X207 Blitz Gundam, and as such it is also equipped with special equipment. One special equipment is the "Geschmeidig Panzer" energy deflection armor installed in its two massive shields. This equipment can deflect any range beam attacks that hits it, making the Forbidden virtually invulnerable to these attacks. Coupled with the fact that the shields themselves also have TP armor, the Forbidden is thus well protected from most beam and physical attacks. In addition, the "Geschmeidig Panzer" also allows the Forbidden to move underwater with ease, even though it is not specifically designed for aquatic use.
Another special equipment is the magnetic field generators installed on the railguns, they allow the bending of the plasma cannon's beam, making the attack harder to evade. Due to the powerful thrusters in the backpack, which is actually a specialized flight unit, the Forbidden can fly in the atmosphere and is one of the rare mobile suits to be capable of both aerial and aquatic combat without any additional equipment.
History
In mid CE 71, the Earth Alliance collaborated with Muruta Azrael's Azrael Conglomerate to build three second-generation G Project mobile suits. These suits used more advanced technology based upon the old G Project mobile suits and were piloted by "Biological CPUs". One of these suits was the GAT-X252 Forbidden Gundam, whose pilot was the "Biological CPU", Shani Andras. The Forbidden debuted during the Battle of Orb, alongside the GAT-X131 Calamity Gundam and GAT-X370 Raider Gundam, and the trio battled the ZGMF-X10A Freedom Gundam and ZGMF-X09A Justice Gundam to a standstill. After the battle, the trio was sent into space and assigned to the Archangel-class assault ship Dominion under the supervision of Azrael; one of the leaders of the anti-Coordinator terrorist group, Blue Cosmos.
During the Second Battle of Jachin Due, the Forbidden was about to destroy the MBF-02+AQM/E-X01 Aile Strike Rouge, but was interrupted by the GAT-X102 Duel Gundam. Using Forbidden's Hresvelgr, Shani shot at Duel twice and an explosion occurred. However, the Forbidden's attack had only destroyed Duel's Assault Shroud armor. The Forbidden was then impaled by the Duel's beam saber and Shani was killed as the Forbidden exploded.
As the Forbidden's Geschmeidig Panzer system could also be used as an underwater propulsion system, the Alliance used the machine as a base to create underwater-use mobile suit, resulting in the GAT-X255 Forbidden Blue, which was also deployed during the war.