Callisto is a chieftain of great renown, known to many as "Calli" or the "Iron Princess". An exceptional tracker and hunter from a childhood among the twin deathworlds known as the Sirens. Callisto was at first, simply another soldier of the Storm Sirens, infantry regiments raised from the tribal hunters that regularly stalk the Sirens' deadly junglescapes that lurk with megafauna and all manner of other dangerous and vile creatures. Through several years of distinguished service, Calli made a name for herself, leaping feet-first into all manner of dangers to get into the thick of combat, particularly against the likes of the Orrc Ravagers or the monsters of the alien Hivers.