Brother Stelin knows not his origins. He was found at the steps of the Church of Irori in Almas, abandoned and alone, a swaddled bundle of green skin and feathery hair. The clerics at the Church brought the unique child to a nearby monastery where the Monks taught him to pursue self-perfection and knowledge above all else.
As Stelin developed, the Brothers at the monastery quickly realized that he had been touched by Outsider blood, causing his unique appearance. The Brothers of Irori helped Stelin hone his natural abilities and gain better control of his powers through personal discipline and meditation.
Throughout his time in isolated training, Stelin never stopped ceasing to wonder about his origins. He knew he was not from Andoran and that he was not destined to spend his life in the monastery. Upon reaching of age, and gaining the title of "Brother of Irori," Stelin set out to further his quest for enlightenment and seek answers about his heritage.
Eventually, he joined a group that called themselves the Golarian Pathmasters, led by Sapphire White. Despite their many successes, forevermore, any mention of that group, or even the word "sapphire" will bring Brother Stelin to that fateful day in Magnimar. He can still smell Sapphire's burning flesh from that weapon. It was enough to make anyone lose faith.
For awhile, Stelin even dropped the title of Brother when introducing himself, if he spoke to anyone at all. He rededicated his efforts to honing his skills, partially blaming himself for the tragedy of the Pathmasters, vowing to never allow such a horrible fate to befall upon another comrade or friend. It's much easier to keep that vow without any friends.
One day, and he still does not know how, a letter from one of his former companions reached him. With a sigh, Stelin read the letter. Setting the letter down, Stelin's face hardened with resolve.
This can only be a sign from Irori, he thought to himself. Here is an opportunity to atone for his previous failure. He must do everything in his power to make things right again, if only so he can continue his tortured journey towards enlightenment. Brother Stelin packed his few meager belongings, grabbed his bow, and set off once again into the unknown.