Mateo is a renowned military commander who is currently living in Prison City for killing his own men during an ambush mission. Even though he does not remember anything from that night because of a black out, he still feels terribly about what had happened and decides to confine himself in Prison City, where he could be surveilled 24/7. He used to be MJ's mentor when they were both still serving, but now he refuses to interact with her and everyone else who were close to him, ever since he realized that he cannot control his power.