The name of the warrior who wore this ancient armor has long been lost to history. The tales of their many battles serve both as an ideal to strive for and a cautionary tale. The Reckless One, as they're known, was unequalled in courage and left a trail of defeated enemies in their wake during their time in the Deadfire.
That is one explanation among several. Popular theory holds that the Reckless One is a title passed down to anyone who dons this armor, and that those with a claim to it are as numerous as grains of sand on a beach.