Well, I had her born in the Blessed Isles before the Ruination. Certain events transpired which had her take up the life of a criminal with vigilante patterns that earned her the mantle of Widowmaker. She was "killed" as part of a deal to make amends with the Black Rose after a particular job she took that involved stealing a precious artifact for Thresh. She revived upon devouring the demon that had preyed upon her soul thanks to the distraction of the Ruination and her intense hatred over the circumstances of her betrayal. She hunted down her former partner, but he had aged so greatly that her anger could not be sated over bullying a geriatric. She attempted to start a "war" on the Black Rose, but gathering information had never been her strength. After a couple years of numerous dead ends, Evelynn resumed the life of an assassin for hire with the calling card of Widowmaker.
After centuries of silence, the Black Rose contacted Evelynn to employ her services. They did so under great caution, sending a demon to negotiate with a demon. Aware that this Shaco was the only member of the Black Rose that had been alive during her betrayal (and having lost all sense of purpose in this monotonous world), Evelynn agreed to become a handmaiden of LeBlanc. Eveylnn has a very strong attachment to Evaine, practically raising the girl since she was three.
