As a kid, Aero burned his arms badly with harsh chemicals while playing with his friends. As a teenager, he and the same friends were some petty troublemakers, got addicted to drugs, some of them died from it, some came off it, Aero never did. Watching his friends die from doing the same as him but never dying himself started a small nickering thought in Aero's brain that maybe he was just immortal and no one had told him. Aero was diagnosed with ASPD based on other things, but never really looked into it. He continued on with his life, got in bar fights, killed a few people in said bar fights. Eventually, a gang picked him up as a thug, but he got pissed at people bossing him around and got kicked out. This happened a few times till he decided he'd be better off just getting groups like them just to pay him to kill anyone they wanted, offering body disposal as a special free bonus. Aero was a little curious about eating people, and it turned to just another addiction. He also bought a chinook puppy off his drug dealer at one point.

He one day met a little girl called Ophelia, and he wasn't interested in being near her. Yet Ophelia followed him. Aero eventually accepted he wasn't losing this annoying brat and finally spoke to her. Ophelia gave him her name and her age, and told him not to touch her. He later found out everything Ophelia touched would die. He begrudgingly bought her a long-sleeved raincoat (with a cat hood) and a pair of long rubber gloves to wear around him, in case she happened to touch him by accident. He let her follow him around and eventually accepted she was going to keep stealing his food and bed, and ended up deciding he'd just have to look after her since she wasn't giving him a choice.

Despite the fact Aero isn't willingly raising Ophelia, he does his best to be a good dad. He read a lot of parenting books in the library and tries to help, but struggles with relating to her and doesn't always seem sincere, even when he is.