In spite of her being the youngest and the smallest in her unit, Zoey is actually physically the strongest.

At the peak of her prowess, she is ranked 2nd amongst all the praetorians and earned the nickname of the "Goddess of War", pretty fittingly since her call sign as a member of the Khaos Vanir Unit is Freya.

For the record, the top Praetorian is Kou Vidar (Izaak Reissner), Zack ranks 3rd overall, just behind Zoey.