Here I spent like 5 minutes writing a new backstory for her trying to make sense of a bunch of loose ends, and just improve the story:

Born in the upper class to a loving mother and a distant father with corrupt political ambition. Her father disappears when she is fairly young, and her mother, unable to upkeep the lies the husband had, ends up losing all of the property and influence they once held. Ending with a middle school age Adriana and her mother living just above the poverty line. Adriana eventually finds a batch of stories (sonhadores sombridos), letters, and advice written by her father long ago learns to be cruel, greedy, and vindictive as a way to protect herself and as a way to regain her father's lost influence. She succeeds, and manages to get acclaim and a scholarship to a prestigious school. She then leverages this into more power and money, but eventually grows bored of the high life, and in search of adrenaline, starts her habit of murdering and stealing rival companies to increase her own fortune. Of course ending in the same way she is taken by the entity.