Very protective over their field trials Biomechanoid weapons, the UEC made sure to destroy every one of them that became unrecoverable.
Some however, slipped through the cracks. One of these was acquired by a group of tech-occultists operating from the asteroid mining colony UE-700P. Lacking both its weapons and most of its armour from the waist up and having sustained a lot of damage to its head, it was nevertheless studied with great interest in light of the occultists own plans to mass produce Biomechs, it was fully taken apart and re-assembled no less than seven times during this process.
In spite of the damage, they found it to be be in remarkably good condition, its reactor fully functional and with 4 of its 5 eyes still working. It was restored to mostly working order, its lost ears replaced with a pair of horns replicating their functions. Inspired by the oni of Japanese mythology, it was outfitted with a new faceplate and a giant club, both forged from the metals mined on the asteroid.
However, the control systems proved to be difficult, it shared little in common with the controls of the occultists own mecha, requiring a pilot suit, the dispenser for which refused to give one to anyone but its pilot, who was presumably dead. Attempts to circumvent the locks were fruitless, the engineers and scientists studying it moved on, taking with them new insight and leaving the Biomech at the lowest level of the mining colony, restrained by chains in fear of a recall mechanism being activated, or it moving by itself somehow. It sat waiting and waiting and waiting, for the day its pilot would come back.