*information as of September 1995

Zack is the son of a couple who had a history of success in athletics. His father was the top runner on his college's baseball team. His mother was the first Karate champion in her home state of Arkansas. One night at age 8, he saw an old martial arts flick where the protagonist utilized Bajiquan to dispatch his enemies. It inspired him to learn the art. Of course, his mother didn't object to it, and luckily, Santa Azul has a dojo for nearly every well-known martial art. He has shown great promise and discipline when learning the art. One Spring day in 5th Grade, he noticed his friend Tim about to get in a car with an obviously shady guy. The stranger told Tim his parents are in an accident and are on their way to the hospital. Zack didn't buy it, so he asked questions only Tim and his parents know. On the second question, the stranger got frustrated and attacked, but Zack was quick to react and took him down and pinned him until the police arrived. It turns out he's a serial child napper who's been luring them with lies like it for 6 months starting at Seattle. Despite the criminal being brought to justice, the case became controversial nationwide because of Zack's involvement. Some think he or his parents should be put on trial for reckless endangerment, but since it's Santa Azul and he presented fair points about Samaritan Acts and the criminal, he didn't stand trial. On his first week of middle school, Tim's mom informed Zack that his parents were comatose after a bombing at a toy store. That left him broken and angry. His aunt flew in to take care of him for the next few months, though she has shown to not care for "the runt of the runt". Of course, he has heard of the bomber and the vigilante group pursuing him and his cohorts, so he searches for them. Upon meeting them, JENNY obviously doesn't want to see him get hurt, so she denied his permission to join. That left him irritated. He tries again, but noticed the group is about to fall into a trap, so he rushes in and sprang them out. After witnessing Zack's ability and persistence, JEN decides to let him join under one condition: Do not use your powers in anger or pursue vengeance.

Although he's a Spirit user, Zack is acting a bit more like a Rage user due to his pursuit of vengeance, therefore his powers are lacking at first. One of his powers allows him to focus in order to tank and deliver hard hits, which goes well with his Bajiquan skills. He also has a Supersonic shout that can either blast enemies back or make their ears ring (he will warn you ahead of time so cover your ears when he does so).