A large part of her personality is due to the way she grew up and was trained, being honed as a weapon from day one. A life like that isn't going to breed a happy-go-lucky party girl, it's going to make her hard and cold. She had to learn early on that detachment was the only way to keep herself sane, otherwise the pain and brutality of what they put her through (both mentally and physically) would be too much. Like how Wolverine's healing factor erased some of his memories in order to keep him from snapping.

But beneath all the conditioning and training and mental scars, she's still just an innocent girl. The target in that first post was the first person she'd ever killed, and it wasn't even her that actually did it. She'll likely be losing that innocence in subsequent posts, but I wanted to show a bit of what she was like at the beginning, before I get to the ruthless killer part of her story.