Casey Strand was born in unusual circumstances. Given up to an underground organization of scholars and wizards, she was kept as more of an experiment than a child. As young as 3 she's been enhanced with spells and magic woven directly into their skin. Multiple dangerous rituals and procedures were performed to try and create the perfect creature, but ultimately it was a failure. A catastrophic accident occurred one night in the stronghold where she was kept, and she took her chance to run. She was only fourteen at the time.
Like a rat, Casey infested herself into the dark corners of the city. Not a single soul could be trusted and food must be fought for. It wasn't until a month of living on her own did she realize her knack and training made her particularly talented at repairing objects, understanding magic artifacts, and sensing their properties. For this, she started earning small amounts of coin to appraise magical items. She saved up, training on her own when she got the chance, and stealing books and scrolls she could get her hands on. When she had enough money saved up, she bought her very first real weapon: A heavy crossbow.
Casey's always remained in the background of the city, preferring to not draw attention due to her ill-formed social skills. But there's a deep longing in her when she watches the community from afar. She sees the bonds that adventurers form amongst each other, and has decided to try and put herself forward for once in her life.