The Arena Saga: Bronze Tier

The High Tower infected Earth's population and only those strong enough to survive the conversion from human to nano-human sapiens were allowed to continue living on the ground level as Bottom Feeders. Over half the world's population fell to the new world order.
Zaphrina is a Nomad Healer in the Golden Arena. Not having the restrictions of a guild has its perks and pays better. Surviving alone in a world where everyone is trying to live forever is easier with the laws of Guilds and Zaph has survived since humanity fell to the High Tower over two centuries ago without joining the halls.
The rules of the Bottom Feeders are easy. You either survive by taking refuge in the Guild Halls or you level up enough to be able to survive the conditions of floor levels. Zaph has it easy for the most part. Her older brother Max has been looking out for her since their conversion. Their parents didn't survive the change.
Max is one of the newest but deadliest Guild Masters in the Arenas and often contracts Zaph to help in battles. He's begged her for years to join his guild, but she's never wanted to be part of them. She likes her peace and prefers to be alone than surrounded by those who would see her dead if the opportunity arose.
Zaph's peace comes to an end when her brother reveals that former members of his guild had fallen victim to the recent murders in NeoGlover City and their son was left orphaned. Cody, the eleven-year-old second-generation nano-humanoid child, stands to inherit a vast territory that could make any guild the most powerful in the NeoGlover sector. Friends turn foes when the guilds find out that this kid has one of the most valuable accounts she's ever seen.
To save Cody, Zaph is forced to solve the twelve recent murders in the city that will grant her an audience with the High Tower council who will remove the territories and return them to the city in exchange for Cody's adult-level updates.