The birthplace of Skarlm Bitterborn is shrouded in mystery, most of those who know him insist that he's ulfen but that's mostly conjecture due to him being a skinwalker werewolf. He'd rather keep it a secret, for the mystique of it.
Now, Skarlm grew up a violent and determined child and in his teens his family had migrated to Westcrown some time prior the shift from Aroden's worship to Diabolism. Thus, he saw the transition firsthand and was so impressed by the sure and unflinching will of the Hellknights that he joined up, becoming a powerful weapon of Asmodeus for some odd centuries, during which he attained immortality.
After earning every medal in the Chelish military he grew bored with their prattling about firm and unflinching rule and cruel but effective justice. He yearned for... CHAOS!
In a startling display of martial skill he turned on his fellow Hellknights and led a spearhead strike against Westcrown nobility. The result was a bloodbath, over one hundred nobleborn met there end by his hand alone, many more slaughtered by his fellow rebels in the wake of his bloody orgy of destruction. The fact that this had little effect on the overall function of Cheliax's government should have alarmed the populace but the attack was falsely attributed to a bauched summoning from a weak-willed Signifer.
Taking advantage of the chaos, Skarlm and many of his 'Harbingers' disappeared into the wilderness of Golarion, to ply a new life in the chaos of nature.
During a raid on a particularly entrenched Asmodean fortress at an undisclosed location, Lord Commander Belisarius was suddenly preempted by a band of Hellknights on the field of battle. The warriors ripped through the Asmodean ranks and proceeded to sack the citadel without mercy.
Admiring their handiwork, the Lord Commander approached the weary assault party and demanded to speak to their leader. Skarlm removed his gore-covered helmet and the two had a terse but fruitful discussion that resulted in the jaded Hellknight's induction into the Epochryphon for a chance to bring sure death and detruction to Asmodean followers everywhere.