This is a setting that Rouji fantasized about an enhanced Caliburn made using spare Caliburn parts, Falact, Demibirding, and parts from machines found on site in Rubrisul in order to annihilate enemy units during the progression of Quiet Zero.
The motif is the AOZ Hyzenthley II Ra.
As it is equipped with two escutcheons, the load is high, so the cockpit is designed to be a two-seater so that the load can be shared between Sletta and Enhanced Personnel No. 5.
However, when Enhanced Personnel No. 5 said, "I refuse to pilot a Gundam," the idea was quickly scrapped in Rouji's mind.

HG Gundam Caliburn Final Battle Specification Ver.RO | ふぇり's Gunpla works