The Transformer was a massive generator built by Megabyte's virals that works similar to a battery, specifically designed to drain and store the very energy of the System Operating Core. The whole chamber relies on two anti-gravity discs to keep it suspended and not only operates as an electrochemical cell - it also converts the Core energy into a "liquid state". In this state it is not filled with so much lethal radiation, but is still obviously dangerous to fall into. Underneath the cylindrical vessel the base features four hydraulic grapplers to keep it attached to the super structure below.
This battery-like container is controlled by consoles from atop the utmost platform.
Megabyte planned to steal Mainframe's Core energy in a surprise attack on the Principal Office. From the safety of his limo he observed his ABC fleet, whilst contacting Herr Doktor for an up-to-date the status on the Transformer. For the most part it remained hidden in Giedi Prime until the Sub-Sphere was destroyed, after that Herr positioned the generator above the facility to capture the escaping power. Megabyte immediately noticed Bob arrive on scene and instructed Hack and Slash to dispose of the Guardian. When this failed he intercepted Bob atop the Transformer before he could disable it. Suddenly the System Voice announced an incoming Game Cube, but something was very wrong as the voice went erratic. The distorted Game was attracted to the Core energy making it extremely unstable. The virus was about to attack Bob when Enzo and Frisket flying the air craft rammed Megabyte straight into the core energy.
The corrupted Game landed on top of the Principal Office, now that Mainframe's Core was inside the Road Warrior Game, the whole reality was comprised. Megabyte had morphed into a truck towing the corrupted Transformer. If the energy was not inside the Principal Office before the Game ended, it would leave with the Cube, win or lose, and the entire city off-lined.
The defenders managed to get the Core back just as the User player was crushed under it. The energy returned through the Cube's wall, utterly destroying the Transformer in the process. Once Megabyte realized his technology was lost he intended to grievously harm Bob for interfering. However, the Guardian was backed up by the entire CPU defense force, forcing the virus to leave. (Bad Bob)