As a young Dragonborn, Koliann's family was in poverty, and she took to the nature of thievery to help her family survive. She never stole from markets or family-owned businesses; her empathy would always prevent her. Even if she did steal from those in the same situation, she would usually return items of similar value to the owners, never wanting to spoil their trade. Koli did not like the wealthy and was heavily an "Eat the Rich" individual, never passing a chance to somehow harm those wealthy enough financially, but never physically.
Later in life, around her late teenage years, she stepped on the wrong rich man's toe. She stole from someone with an intricate system to keep their valuables; worse yet, she left evidence leading to her. Knights were then sent to destroy her home and family with no second guesses. As it turns out, she had not been home then, only to arrive at the disaster when she couldn't save her family.
A thieves guild found her after making a survival camp near her destroyed home. It took her in, training her as a thief, given her blooming history of crime regarding the rich. She fought well enough to feed herself, and she had started taking on the role of assassinating influential figures who were tyrannical. She often wore dark clothes, including a cape with a hood and a black mask highlighting her red eyes, giving her the title of The Red-Eyed Shadow as a thief. However, after a scuffle with Raznov Ivanov her identity is revealed after her mask is shattered, which ruins her reputation within the guild. Eventually, Koli feels affection for Razz despite him destroying her bonds, leading to her taking the chance for a new life and escaping the guild with Razz, fleeing to Absalom. Even then, she couldn't escape from her thieving past, and while she trained as a monk, her roguish tendencies remained.