Iron Hawk
Sigrid von Mienbad was born in Uruguay to dedicated, unreformed Nazis. He grandparents had used the "ratlines" to escape Europe after WWII, had a bunch of kids and inducted them into their ideology. Her parents were at first hesitant about giving up their daughter for training as a spy and assassin - a good Nazi girl's job was to marry and have lots of Nazilings - but she was spirited and headstrong, and they saw a chance to give her what she wanted while doing their part for the Cause.
Sigrid was taught the arts of stealth, infiltration, acting, seduction. She also learned to use various weapons, ranging from blowguns to artillery, though she had a particular liking for knives and the Filipino art of Kali . She made her first kill at 13, using her youth to get close to a pedophile politician - she was so disgusted by him she first paralyzed him with a toxin, then castrated him and allowed him to bleed out. (Her handlers rated this only a 9 out of 10 - he could have been saved if he'd been found before he exsanguinated.)
However, Sigrid is a highly intelligent individual. Shortly after she turned 18 (and just after her 35th assassination), she murdered her handlers, obliterated all their records of her in a fire, and went freelance. She recognized her parent's ideology as obsolete, stupid and worthless in the modern world, and she has no use for inferior ideas.
Sigrid's skillset is all about killing. She is quite capable of gathering information, exploring areas, and scouting, but she sees these as secondary to her real job of ending lives. She is not dispassionate about this - on the contrary, she quite enjoys her work. In her time she has killed men, women, children, anything she gets paid for, or who gets between her and her target. Her fellow Ninja view her as a go-to for pure wetwork.