Security Officer (Marathon)

The Security Officer, also known as Mjolnir Recon 54, is the player character and main protagonist of the Marathon Trilogy

Overview
His background not truly known, The Officer was a security guard working on the Marathon space colony. However, an alien race called the Pfhor attacked the colony, forcing The Officer to defend it. As he did, he discovered more about the ships history, as well as the context of the current issue, and how it was much more than it apparently seemed.

After the events of the first game, the Officer was kidnapped by Durandal and put into stasis for 17 years. He awakened on the planet Lh'owon, homeworld of the S'pht. He then began his journey to go find more advanced technology that Durandal could use to defeat the Pfhor

After that, the Pfhor used the Triah Xeem, a weapon designed to force a star into early nova. However, this resulted in a chaotic being called the W'rkncacnter being unleashed. It began to devour reality, and The Officer started jumping across multiple timelines to find a way to stop its chaos, while also learning more about his own history and identity

Personality
From what little we know abut his overall disposition, The Officer seems to be a dutiful soldier, albiet a somewhat detached one. He tried to the best of his abilities to save the population of the Marathon, as well as the Tau Ceti colony it overlooked.

The Cyborg's mind and personality are mostly left up to the player to speculate on. Although Durandal describes him as "a magnificent killing machine" and asks him if being allowed to kill more Pfhor will "make you happy," the AI is more likely being malicious than accurate. While the Cyborg does not seem to be a mindless psychopath, he is clearly comfortable enduring and quite capable of carrying out violent acts on a scale unimaginable to any normal person. However, in the third game of the series, he seems to lose any sense of morality he may previously have possessed, working for the indisputably evil Tycho and killing BOBs on Tycho's orders in a desperate attempt to keep the W'rkncacnter trapped in Lh'owon's sun. In Marathon Infinity, we are given greater access to his mind and feelings. He seems to recognize some sort of guilt or weariness for the atrocities he has committed, and appears to believe that he has been forced to do what he has done. Ironically, this seems accurate. All three games consist chiefly of doing what various people tell him to do - only once does he act of his own initiative, and this is in the Marathon manual, which is not an entirely reliable source.