Long ago, Arwyl Swan’s Son was a divine champion of Torm in Toril. After chasing a fiend through a portal and becoming grievously injured in the battle, he was rescued by a Mercykiller. The stranger dazzled him with glorious tales of justice’s ideal, recounting his exploits and victories against demons and other agents of chaos. When Arwyl was well enough to travel, he journeyed to Sigil to pledge service to the faction. Not long afterward, Arwyl realized that many Mercykillers sought a brand of justice at odds with his own. Though he suspected such people sought only to serve their own evil ends, he refused to break his vows. So he worked within the faction to guide it toward virtue, even though he failed as often as he succeeded. When the Mercykillers collapsed during
the Faction War, he was the ideal candidate to lead the newly constituted Sons of Mercy, a role he has filled for over a century.