This is kind of like a mash-up of Hunger Games, GI Jane, and Tananarive Due's African Immortals series (because of its obsession with blood). The protagonist is a little dumb and a lot violent, but you have to excuse her because she's Black and female and blessed with God-granted superpowers in a society that hates all three of these things. Also her grandfather, who raised her, recently died, and she just discovered that he was actually murdered. Plus, what with the superpowers that make her faster and stronger and quicker to heal than the average bear, if she weren't a little ignorant and slow to catch on, she would have zero weaknesses and there wouldn't be much of a story.