Slumdog Hero: A Progression Fantasy by L.C. Cardeon

In the slums beneath the wall, power is the only law. For Fii, survival means keeping her head down and staying out of trouble. But after a brutal gang attack leaves her broken and desperate, she gambles on an experimental treatment from a disgraced geneticist. It gives her something the city has never seen before. The ability to bend gravity itself. Now Fii is thrown into a world of ruthless training, turf wars, and blood-soaked alleys. To protect the people the city abandoned, she becomes a masked vigilante fighting back against the violence consuming her home. But a deadly new drug is spreading through the district, turning users into raging killers. As the body count rises and gangs tighten their grip, Fii must push her newfound powers further than ever before.