Do not read unless you have already read the series or don't care about plot twists.
Born Alex Greene before bonding and marrying Handler Theo Taylor. Eventually bonded and married Handler Marcus Stephanek and became Alex Taylor-Stephanek.
Air Force brat, family retired to New Mexico when Alex was 15 and already attending Pendleton Academy.
Alex is likely one of the most important Protectors ever born. He manifested as a Protector at the absurdly young age of eight and was an object of study from then on. His survival of Theo's murder was unprecedented.
It is from Alex's blood that Dr. Kensington created his illicit serum that revolutionized Guardsmen culture, the effects of which are still ongoing throughout the series.