The Big Gun is an Evil Baby Corporation structure. It is a support structure used to deliver units and/or supplies a long distance rapidly, although with some inaccuracy. It may also load explosives and thus work as an makeshift artillery battery, but with even greater inaccuracy.
The EBC learned a harsh lesson on the importance of logistics as the First Lampardian War turned to their opponents' favor after the disaster at the Battle of Telemantros. With the initiative in the Eleutheroi hands, Eleutheroi proceeded to isolate the EBC locations, denying the outlying outposts from supply. While this may have not been a trouble before the Battle of Telemantros which led the Eleutheroi to seek air superiority, this was after the said battle, and the Eleutheroi were in control of the air, having anti-air batteries as well as jet fighters which denied them the option of airlifting supplies through the remaining airships not totaled by Sematia Aiakida.
After the loss of the First Lampardian War, the Evil Baby Corporation had to recuperate. They did so with the Brawl War, from which they adopted several new tactics, such as directly dropping the personnel and equipments from space, and also the man-cannons. Finding the man-cannons a particularly useful choice in places where space and air is contested, Kakistargyrion immediately adopted the man-cannon tactics, and had designed a giant cannon able to launch squadrons out into the field in short notice, fast enough to prevent interception if undetected before launch. However, the result of enlargement also resulted in lack of accuracy and precision, meaning these cannons are ill-suited to serving as actual artillery battery, improvization at best.