Special Rethiarius Chaos

The Special Rethiarius Chaos is the final boss in Facility 902. In this fight you use a special cannon, (the left platform when you first walk in boss area) to shoot down the boss. Using the cannon you will shoot the boss and the little Mechanoids that spawn in. He will form a pentagon and shoot a focused beam at the player for several seconds. When he does this it is best to leave the cannon and kite the boss till he stops.