Atlas Amspoker was born with a tolerance to The Sickness, due to his mother's ties with the monster. He was brought up in a broken home; but it wasn't always that way. His parents, Tracy and Adam Amspoker, were once loving and doting.

Atlas's seventh birthday came- The Operator made itself known, digging up a long forgotten lifetime of trauma for Tracy. Tracy grew withdrawn and closed off. She resented Atlas, holing up in her room, losing her job and shutting herself away from the world. Adam took on longer hours at the hospital he worked at to make up for this- all Atlas had was his twin brother, Apollo, and Apollo had his own number of health issues to deal with.

Cygnus Shirotori comes into play.

When Cygnus meets Atlas, they're only kids- Cygnus takes a liking to Atlas's skittish nature. Come to find they're both "friends of the tall man." Cygnus's obsession begins here. Cygnus, over the years, befriended and isolated Atlas. Brainwashing him- “I’m the only one besides you who sees the Tall Man. I’m the only one who understands you.” Cygnus was awful, obsessive— and it only got worse as they grew up. Their relationship grew into something unlabeled- not quite platonic, not quite romantic. Something that transcended beyond words. Atlas takes Cygnus's torment and torture, because it's always followed by the affection he craves. The two bond over their shared experiences with the sickness- the hallucinations, the physical illness, the psychosis. Only they understand one another.

It all comes crashing down during their school's end of year senior dance— that’s how Atlas ends up getting that burn scar. Trying to stop Cygnus from setting the school ablaze in an attempt to "feed the ark." Atlas realizes this has gone on too far- he can't allow this "love" of theirs to bring the end of others.

Atlas changed after this; closing off his emotions and feelings to the world. He never wanted to be taken advantage of again, so he toughened himself up by force. He got a job, and despite the constant stalking and torment from The Operator, he planned on moving out- though Tracy did not like this. In a fit of hysteria the night before Atlas was to leave, Tracy attempted to take his life. She didn't want the sickness to spread any further. She had planned to take out Atlas, and then herself. Atlas, fighting the knife away from her, accidentally caused her to stab herself. The static was so loud by this point. He'd done what Cygnus couldn't do- he'd fed The Ark. He made the sacrifice to The Operator, though he did not want to.

Certain nobody would believe his side of the story, he ran...far off into the woods, where he was reunited at last with Cygnus. Until the day of Cygnus's death, the two remained loyal pawns to The Operator.

Atlas, because he was born with The Sickness, has developed a high tolerance to its symptoms. Because of this, he can withstand being possessed by The Operator for short increments of time- though he can't go too long before he seizes and collapses.

Other tidbit of information: Atlas chalks up all of his trauma to Cygnus, but fails to realize that a portion of it was his parents neglecting him, and his mother's scorn for him. He thinks that his hyper independence is solely because he can't rely on someone like Cygnus ever again- but his mom shut herself in her room for almost his whole childhood and resented him. His dad was always at work. He's been fending for himself since he was a child.

It's why he so desperately clinged onto Cygnus and fell so hard for him.