UO's personality is basically just the saying "That's how the deck is shuffled", meaning he'll adapt to the new situation in front of him.
185's personality is just focus, he's always at the ready to get out and do his job at the flick of a wrist when in hours. Outside of those hours though, he's like an uncle to UO, because he basically is an uncle to him, as UO's trainer knew 185 like a close friend.
Vernon's personality is that he's mainly chill, but aware. He's always aware that he's being hunted by someone and is always ready to react with haste.
Jeremy's personality is also just focus on his shift, but outside, he really likes walking through forests, nature, really, anything away from society. Nobody knows why though, so the working theory is that he just likes the sounds of nature.
Gas Mask's personality is. . . well, it's kinda hard to put it into words, so I'll put it into an image.
