Nebula is mostly machine, and all the other parts of her are alien like Gamora, yet I'm the most attracted to her out of all the cast of Guardians of the Galaxy. Maybe it's that I like wounded women with daddy issues. Nobody has more daddy issues than Nebula. Even Gamora's issue pale in comparison. At least Gamora still has most of her natural body parts. Thanks to their father, Thanos, the two of them fought it out for most of their lives.
I'm glad they kept her around as a villain/friend instead of killing her off. She's an interesting villain because you can sort of see her point. She's like Loki in that she lives by her own code instead of prescribing to being a good guy or bad guy. A truly independent woman.