Based on the original FF-X7 Core Fighter, the FF-XII Core Fighter II was designed as part of the Core Block System of RX-78GP01 Gundam "Zephyranthes". Normally serving as the cockpit of the Gundam, it doubles as an emergency escape craft. The fighter also serves splendidly as a scout craft, a role that it can perform more efficiently than any mobile suit of the time.
The Core Fighter II features several improvements over the original: First, it has a more streamlined and aerodynamic design, which helps to offset that it is both longer and heavier than the original. A second noted improvement is that unlike with the original Core Fighter the Core Fighter II is equipped with the RX-78GP01's beam sabers, that are mounted under the wings in flight mode. These beam sabers double as beam guns for the Core Fighter II giving it a ranged attack. Core Fighter II's thrusters also function as GP01's thrusters instead of being deadweight like the original Core Fighter.