Born and raised in Unova, he comes from the area around Opelucid City, having grown up in a small rural community that has been commonly called the Village of Dragons for a long time now. Only thing is, he never got a dragon-type Pokémon. The egg he had received as a kid turned out to be a rather large Larvesta hatchling that was accidentally swapped with the dragon he would have gotten. However, since little enough was known about them, he ended up having the poor thing forced on him, so that information could be gathered about it. Not only that, but since the egg had already hatched, the two were stuck with each other from that point on anyway, and Adrian never ended up getting that dragon (which were typically either Axew or Dratini for children of that area). He ended up calling the hatchling Supernova because of her bright personality, along with the fact that she seemed to have a certain glow about her. (It wasn't until later that he learned that she had the ability Drought, which is unusual for most typical Larvesta.)
Instead, he was given the opportunity to earn it, as he had graduated school a year early, at the age of 9. After having some unsuccessful adventures, he stayed home for a couple of months and trained until he was ten, which was the normal age for kids to get their trainer's licenses and go on their journeys, regardless of their length. This one turned out to be a fair success, in spite of the fact that he never worked up the courage to challenge any gyms. Therefore, he never got very strong, and instead focused on having a good time out on the road.
He was ten now, and by this time, he had already caught his Gastly (who he had named Superman because of a prank the ghost had pulled early on), and his newly-caught Shellder (which he aptly named Frostbite). He would have had the time of his life, and was even contemplating challenging his first gym, when the worst happened. Several criminals showed up and abducted him in a rather noisy show of force, which didn't fail to attract the stronger authorities (namely some members of the Unova Pokémon League, along with the police in general). However, they weren't fast enough to prevent the damage from being done.
They were part of an unknown organization (likely an off-shoot of the dead Team Plasma) that was trying to replicate the Mewtwo Experiment that Team Rocket had attempted so many years ago, but with a human. However, the initial experiment (given in the form of a shot this time) was a near-complete failure, which much more harm having been done than good. Before they could do anything worse to try to compensate for the initial failure, Drayden himself charged in and rescued Adrian from the criminals, destroying their lab in the process -- and his powerful dragons accidentally destroyed most of the equipment during the battle as well.
As such, nothing conclusive was found regarding a cure for the terrible condition they ended up inflicting on the boy. So far, the only real benefits he's gotten are increased intelligence and the ability to speak to and understand Pokémon, just as N could when he was still around. In addition, he's able to battle far more effectively on his best days somehow, likely due to the fact that the serum he was given contained genetic materials (and unstable ones at that). In return, he got a world of pain and suffering, and even his use of his newfound abilities are severely limited, except for his ability to understand the world of Pokémon in a way that few others could.
After a couple of hard years of trying (and failing) to either recover from or cope with his new conditions, he's gone to the Academy to find a cure, or at least find a way to live with his condition. However, he's not trained his Pokémon up in their strength. Instead, he's worked on their ability to battle without his commands, so that if he's caught in a bad situation on a bad day, his Pokémon can at least defend themselves. While he is here, he hopes to grow stronger in addition to finding a cure for his illness.
