Leo

Overview Leo (short for Leonardo) is a security guard that works for the GRN and is stationed at the company's Northern Branch in Alaska. He is a major participant in Flim's plan to prevent the Apocalypse. Personality

Leo is an oddity among the other characters of the show as he is seemingly immortal. He does not age, cannot die of natural causes, and is mostly immune to physical trauma, with the exception of bruising. He does not know why he is immortal; he only knows that he woke up in 1993 and has existed ever since. Previous attempts to discover the reason behind his immortality have proven fruitless, but after the events in the Canyon, his drive to uncover the secrets of his origin has been renewed.

Leo initially carries one of the strongest weapons out of both teams; a railgun. However, he is hesitant to unleash its strength upon anyone, viewing his immortality as an "unfair advantage." Later, though, he relinquishes his pacifist ways to save Joey from Maylor's attacking Mech-Tank. When Butler destroys the railgun in their final battle, Leo takes the mercenary's powerful Zap Cannon as a trophy.

Leo is one of the most intelligent and clear-thinking members of the Odd Men Out, and can be one of the kindest, but is not without his harsher moments. While he was initially reluctant to take charge of the group, the battle with Butler helped him to realize his true role as leader. He tolerates most of the group fairly well, but has been known to get fed up when they are acting stubborn or foolish. His closest relationship is with Joey, formed out of the necessity of a remote work environment, but maintained by some kindred spirit. While on the surface it seems that all they do is bicker and insult each other, if one were to see them at a vulnerable moment, they would find a truly heartfelt and caring, almost brotherly, friendship. Leo will scold Joey without hesitation and does his best to keep him in line, something Joey acknowledges as necessary. Meanwhile, Joey does his best to encourage Leo when he is feeling down or worried about his predicament, and violently defends him against those who would label Leo a freak.

Leo seems to regard Tyler as a little brother, but is much more protective of him compared to Joey, and is much more tolerant of the young member's shenanigans. Even Leo has his limits, however, and once and a while will reach his breaking point with Tyler. As for Mack, Leo initially has little respect for the former GRN leader, but this plummets to an outright hostility soon after Mack returns from the dead and acts suspicious. Leo is the one to catch Mack in the act of betraying them, and when reunited with Mack at the Necromancer's lair, Leo views him with contempt. However, after Mack rejoins the team, saves them from The Necromancer, and aids them against Butler, Leo seems to have at least a little respect for the undead member.

Leo seems to mostly get along with the ORNGEs, as he is one of the few who understands that the two teams need to work together, but seems to get along best with Muppet, who is the only other equally level-headed and logical member out of both teams. He is frustrated with Flim's refusal to tell him more information about his immortality but otherwise does not seem to like or dislike the demon.

Leo does not like Seth's negativity but is MUCH more lenient and understanding towards him than anyone else present. By the end of the second season, though, Leo agrees with Joey that he would prefer not to meet Seth again.

Leo has a fierce rivalry with Butler, being one of the only characters to bring the fight to the crazed mercenary directly (likely due to his immunity to physical harm). Butler, however, is one of the only characters who can affect Leo at all, being able to knock him out with the tremendous energies of his Zap Cannon. During their final battle with the mercenary, Butler destroys Leo's railgun, but Leo soon replaces it with the Zap Cannon after Butler's defeat.

The Necromancer seems to know quite a bit about Leo, and it is Leo's hunger for information that leads him to strike a deal with the mysterious, evil being. The bargain falls short, however, leading Leo still inquisitive and frustrated, possibly starting him down a dangerous path as he hunts for answers to his questions. Trivia
 * Leo is voiced by Joshua Mies.
 * Leo is the first sign of the show's growing supernatural influence.
 * Leo's immortality may be a spin on Church's tendency to survive injuries that would be fatal to a normal person in "Red vs. Blue".
 * Leo's theme is "Lonely Soul"