The Chained City-Book One-Night Dragons

The weak are but stones for the strong to stand upon. That inscription is written on the statues the people of Ninleth worship as gods. Half human half monster giants that live in the mountains and the people of Ninleth city obey. When Bree Hearthstone breaks the law of caring for the weak orphan children, she is punished by the elders and sentenced to spend the night on the city wall where beasts wait for their evening meal. Ash Ironwood attempts to save her but is badly injured and dying. That is until the Wanderer, a mysterious man who walks many worlds gives Bree and Ash a special gift. The System! They find themselves in the Academy for Warriors and Mages, but they don't fit in and are forced to fight for their lives. But they have a secret weapon, the system. An old ranger is a special instructor for the semester and offers to teach them, but he isn't the only one that plans to be their teacher. Ash and Bree grow stronger each day and vow to fight the darkness at the heart of the city and for the weak the city despises.