Mackie Stingray is Sylia Stingray's younger brother and her only family. He serves as the Knight Sabers backup and mechanic along with Sylia's friend, Dr. Raven. Mackie is a whiz kid with computers and technology. He has to constantly make repairs to Priss's bike because of her driving and the situations she gets into. He can pilot an armored suit himself and drives a large truck that delivers the Knight Sabers and their bikes to a situation. Mackie's character is also extremely perverted, trying to catch his sister (as well as the other Knight Sabers) in the nude as much as he can.
In the 2040 storyline Mackie is much more polite. His sister Sylia tries to keep Mackie from becoming involved, but he helps the former Genom employee named Nigel at his rundown motorcycle shop and builds and repairs the team's Hardsuits. It is later revealed that Mackie is actually a prototype Boomer that has a more advanced brain modeled after Sylia's own brain functions. In both versions, Mackie also shows romantic feelings towards Nene Romanova.