Fortress Maximus is one of the largest and most powerful of all Transformers. He is the leader of the Cybertron Headmasters, and takes command of the entire Cybertron army after Seibertron is destroyed and Rodimus Convoy leaves to search for a new homeworld. As a Headmaster, his head transforms into a smaller frame while his body transforms into a defense base/spaceship. There is no difference in personality or memories between the larger or smaller robots.
Because Metroplex is permanently grounded on Earth, Fortress Maximus is called upon to fight against the giant Megazarak whenever the Destron decides to spread his evil. To unite with his enormous body, he must concentrate all of the power within his body, which simultaneously allows him to merge and releases the Master Sword. The Master Sword is the main weapon that Fortress Maximus uses in his battles with Megazarak. He can manipulate its size so that it becomes large enough for battle or small enough to be stored inside. Fortress Maximus has not been beaten by Megazarak, no matter how much trickery or how many special weapons (like the Zarak Shield) Megazarak has used. He always gets the upper hand in battle, only to have Megazarak escape at the last second before the death blow can be felled.
Fortress' main weakness is his need to concentrate his powers before transforming. If he is weakened or low on energy, he is unable to compose himself and unlock the Master Sword from its holding area. He sometimes has to rely on the other Cybertrons to cover for him while he recharges himself. Fortress Maximus has shown the ability to absorb enery from the outside environment, which helps to speed up the necessary resting period.
As a leader, Fortress Maximus is level-headed and cool under fire. He is compassionate toward other living beings, and does not a zest for battle. He would rather not fight unless he absolutely has to, probably because of the toll it takes on his energy reserves. Since Rodimus Convoy is still alive, Fortress Maximus does not carry the Autobot Matrix of Leadership, but that does not mean that he lacks the wisdom or courage to be a good leader. Actually, he is well respected and appreciated by his troops possibly because of that fact.
