Sapphire (Book One, Arrow)

Jillian "Jill" Wright has been through hell, and when she's stranded on an island, that hell only gets worse. She loses her sister, Amy, and she's all alone until she finds Oliver Queen, Slade Wilson, and Shado.
She can't go home, and she has nowhere else to go, so Oliver brings her to his home in Starling City after years on that island in the middle of nowhere.
And they both have scars and secrets buried so deep that they can't seem to move on without finding a cause.
They both take into consideration of protecting Star City.
Oliver becomes "The Hood", otherwise known as Arrow.
Jill becomes Sapphire.
Even though there is a tension that is clearly seen between them with such intensity, Jill won't let anything happen until Oliver stops being the killer that he is and becoming the hero that she knows that is inside.